P2138 in 2026: Pedal Sensor, Wire, Connector or Throttle — What the Maker Papers and 915 Owner Complaints Show

P2138 is a code about agreement. Modern cars have no cable between your foot and the engine: sensors in the pedal report how far it is pressed, each pedal carries more than one position signal so the computer can compare them, and the computer opens the electric throttle. P2138 — named by GM as "Accelerator Pedal Position (APP) Sensor 1-2 Correlation" and listed in the generic OBD-II code list as "Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation" — says two of those pedal signals do not agree with each other. The usual result is reduced power: a limp mode, a wrench or engine light, a message such as "Engine Power is Reduced", and a car that accelerates weakly or, in some cases, barely responds to the pedal. GM says the pedal itself still functions; it is the power that is cut.

This page answers whether P2138 is the pedal sensor or the throttle, why the car goes into reduced power, whether you can drive it, and what it costs. In short: the printed causes are mostly the pedal's plug, wires and harness, water, software, and on a few models a broken solder joint inside the pedal; the throttle body belongs to the sister code P2135; and the money runs from $0 under a recall or coverage to several hundred dollars for a part, and more when parts are replaced one after another.

What is in scope. This page covers P2138, the pedal-circuit codes the documents list with it (P2122, P2123, P2127, P2128), and its throttle-side sister P2135 (throttle position sensors 1-2 correlation), because both are two-signal agreement codes, Ford's TSB 18-2062 lists P2127 and P2135 together, and owners write about them in the same sentence. P2136, P2137, P2139 and P2140 are almost never named: no document we read prints any of them, and the complaints name P2137 once and P2140 once. The throttle motor faults (P2101, P2111, P2112, P2119 and similar) are a different fault. Complaints that blame only a throttle body or its motor were left out of this count by a written rule; our throttle body replacement cost guide covers that road.

What we read. The carmakers' repair papers on NHTSA's site: 158 distinct documents, 111 read in full and 47 compared with them; 22 of the files name P2138, and none names P2136, P2137, P2139 or P2140. And 1,182 federal owner complaints received from January 2015 through early October 2026, sorted twice, independently, by the same written rules: 915 describe a pedal or throttle position-signal fault on the owner's car, and 230 of those mention P2138. Counts here are complaints, not cars, and nothing is a failure rate.

By the end you will know which of five routes your P2138 is on, what each costs, which recalls and coverages exist, and when to tow.

Claims marked 🟢 rest on a document listed in the Sources section. Claims marked ⚪ are shop-price estimates carried from our repair guides. Owner-reported figures are what people told NHTSA, published with NHTSA complaint numbers, and every complaint count here comes from the 1,182 complaints sorted twice and published. The documents are listed with their reading status.

Words on this page. APP sensor: the sensor in the gas pedal; TP sensor: the throttle position sensor. Engine computer (ECM, PCM): the car's computer. DTC: a trouble code. Reduced power or limp mode: the computer limits power and speed. Bulletin (TSB, SSM): a maker's repair instruction to dealers, not a recall. Emissions recall: a recall about emissions equipment. Special coverage: a maker's own free-repair program, not a recall.

I built PulsCar after a $380 "full diagnostic" in Phuket in 2025 led to roughly $6,000 over six months across several shops (the story is on the About page).

What P2138 says: two pedal signals that do not agree, not a dead pedal

What the code compares. 🟢 GM's water bulletin prints the code as "The technician may observe on a scan tool DTC P2138 – Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History." and explains the setting condition: a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for longer than a set time. 🟢 Honda's dealer message prints it as "Accelerator Pedal Position Sensor A/B Incorrect Voltage Correlation", and Mercedes-Benz lists it in its own form, P2138F1 and P213800, as pedal position-sensor values that are implausible relative to each other. The word that matters is the same in all three: the two signals disagree. That is a statement about agreement, not a verdict on the pedal.

What you feel. 🟢 GM's recall letter for the 2014 Cadillac ATS says the code "may set as a result of the associated high resistance, causing both traction and stability control systems to be disabled, reduced engine power mode operation, and the Malfunction Indicator Lamp (MIL) to illuminate." GM's special coverage N182188250 describes it from the driver's seat: "accelerator pedal will still function, but the vehicle will enter a reduced engine power mode in which" maximum acceleration and torque are reduced. 🟢 Ford's message for the 2015-2017 F-150 lists "intermittent loss of throttle pedal response, illuminated wrench" and other warnings with P2138 among seven codes. Among the owners who wrote to NHTSA, 738 of 915 complaints describe reduced power or a pedal that did not command the engine (81%), and 151 describe a stall or a loss of drive (17%); Subaru owners add a flashing cruise-control light, which 34 of the 89 Subaru complaints describe.

What it is not. It is not the throttle motor fault (P2101, P2111 and relatives, see the throttle body guide), a brake-pedal sensor fault, or a pedal that sticks or a car that surges: this page is about too little power. When the car will not accelerate at all, our won't-accelerate guide is the wider map, and the stalls-while-driving guide covers the car that dies.

Is P2138 usually a bad pedal sensor, and should the pedal be the first part you buy? PulsCar went through 1,182 federal complaints from 2015 to early October 2026 that name P2138 or a sister code, or describe a pedal or throttle position-sensor fault, each sorted twice by the same written rules: 915 describe the fault on the owner's car. The pedal ends as the named or replaced part in 237 of them, a wire or connector in 56 and a throttle part in 81, while 466 name no cause at all. Among the 230 that mention P2138, 25 end at a pedal, 16 at a wire or connector and 3 at a throttle part. The maker papers are less pedal-centred: they print water, crimps, chafed harnesses and software, and among those that name P2138 only GM's 14636 (a broken solder joint inside the pedal) and N182188250 call for a new pedal. Test the plug and harness first.

First: P2138, P2135, P2122, P2127 … which one is yours

Read the exact code before you buy anything, because the same fault family carries different labels in different makers' papers.

The labels differ by maker. 🟢 Lexus prints a neighbour, "Throttle / Pedal Position Sensor / Switch "A" Circuit Voltage Out of Range" (P01201C), and fixes it with an engine-computer flash. 🟢 Nissan prints P2135 as "P2135 - TP SENSOR-B1". 🟢 Mercedes-Benz lists P2138 only as sub-codes of its own form. A scanner label tells you the circuit; the paper for your car tells you what the maker found.

Search traps. A few owners write "P02138", "P-2138" or just "code 2138". Many describe the same fault without any code: of the 915 complaints, 584 name no code from the P2135-P2140 family or the pedal-circuit set, so do not rule out this fault because your paperwork has no P2138.

The maker atlas: who prints a wire, a plug, water, a solder fault, software or a recall

The documents split by maker: a Malibu, a Mercedes E-Class and a Ford F-150 with P2138 are on different roads.

The GM water bulletin is the clearest P2138 paper in the file. 🟢 GM's 07-06-04-019E says the condition "may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM." The correction is to find and repair the water leak, then inspect the connector terminals for corrosion and debris; it adds "Aftermarket equipment can generate DTC P2138 and/or other DTCs." 019F, dated November 2017, repeats it for 2018 and prior models; both name the 2014 ATS and send the shop to recall 14176 first.

Most mentions are incidental. In the Stellantis flashes, throttle-position codes sit among many other codes and the fix is software; none says to replace the pedal.

The do-not-replace lines: what the papers tell a shop to hold back

Several makers print a line like these. None says the pedal is never the cause; each says that, for the complaint described, something comes before it.

• GM Malibu, LaCrosse, Regal (N182188250): 🟢 pedal only if GM's test points to it. The shop is told to "Follow the diagnostics located in SI for DTC P2122, P2123, P2127, P2128, or P2138 to determine if the accelerator" pedal sensor needs replacing (SI is GM's service information, the dealer's repair manual), and that "If diagnostics do NOT lead to the accelerator pedal position sensor replacement, no further repairs are covered".
• GM LaCrosse, Allure, Impala (14636): 🟢 the pedal is replaced, but only after the dealer verifies that it needs replacing, with GM's bulletins 07-06-04-019 and 08-06-04-041 for reference; if it does not, further diagnosis is not covered.
• Mercedes-Benz, models 213 and 238: 🟢 "Please do not replace any other components (e.g. accelerator pedal sensor)." It follows a connector and feed-line repair ordered after the maker's test steps show no component fault.
• Chrysler pedal tips: 🟢 "Make sure codes are active before replacing pedal." The reason is printed beside it: "P2122 and P2127 will set if accelerator pedal connector is disconnected during diagnosis." For P2299 the tip says the pedal "should not be replaced for this fault if driving style is confirmed with the customer."
• GM 16-NA-012, 2010-2015 Equinox and Terrain: 🟢 pedal and harness only if the connector is damaged: "If damage found, proceed to Step 2. If no damage found, follow normal SI diagnostics."
• Jaguar Land Rover, 2015 Range Rover and Range Rover Sport: 🟢 a pedal is replaced only when its serial number is on the maker's list.
• The throttle side (P2135): 🟢 GM's bulletins say "Attention: If a vehicle is encountered with this condition, DO NOT replace the throttle body. Instead follow this procedure below." The procedure replaces the sensor cover first, and the throttle body only if the two sensors still disagree (Route 5).

The pattern: in the papers about P2138, wire, plug, terminal, water or software come before the pedal. The exceptions name a defect inside the pedal itself: GM's 14636 for a broken solder joint, Jaguar Land Rover's program for a soldered switch board, and Kia's campaign for a mispositioned part; GM's N182188250 also replaces the pedal, but only if its test points there.

The 10-minute check

1. Write down how it started and what the dash said (2 minutes). Rain, a wet floor, work under the dash or an aftermarket device, or on its own? Which messages: "Engine Power is Reduced", a wrench, a flashing cruise-control light? Every drive or once a week? Read the codes with a reader that shows pedal codes and note whether they are current or in history (GM's bulletins distinguish the two). Do not clear them before a shop sees them; that is our advice, not a maker's rule. Do not unplug the pedal to "test" it: 🟢 Chrysler prints "P2122 and P2127 will set if accelerator pedal connector is disconnected during diagnosis."

2. Look for water (3 minutes). 🟢 GM's bulletin puts the connector in the left-hand kick panel area or inside the instrument panel and lists the sources of water to check: A-pillar seals, sunroof drain lines, windshield and cowl sealing. Wet carpet by the left kick panel, or a leak you already know about, is a reason to mention the bulletin number to the shop. 🟢 GM's bulletin also says "Inspect the IP to body harness connector terminals for corrosion and debris."; that is shop work, not a driveway job.

3. Look at the plug and the harness at the pedal (3 minutes). Is the pedal plug seated and clicked? 🟢 GM's 2016 Silverado HD and Sierra HD service update asks the shop to "Verify that the CPA for the accelerator pedal position sensor connector is fully seated." (the CPA is the connector's locking clip) Is the harness near the pedal pinched or rubbed? 🟢 Ford's papers name the harness routed behind the brake booster; GM's name a pinch under the dead-pedal bracket on 2018-2019 Corvettes and under a junction block mounting leg on 2016 Silverado and Sierra.

4. Find your VIN and paperwork (2 minutes). Special coverage, emissions recalls and warranty extensions often do not show in the safety-recall lookup at nhtsa.gov/recalls, so a dealer with your VIN is the lookup. Ask by number: 14176, N182188250, or Mercedes' pedal wiring harness extension. Note your mileage and the date the car was first sold.

Six P2138 situations, and which is yours

"A 2016-2018 Malibu, 2017-2018 LaCrosse or 2018 Regal with Engine Power Reduced and P2138." GM has special coverage N182188250 for certain cars like this: it can apply if the car was first in service less than 10 years ago and has under 150,000 miles, and only if your VIN is on GM's list; a dealer checks that. → Route 1; the pedal is replaced only if GM's diagnostics lead there.

"A 2014 Cadillac ATS with P2138." GM's emissions recall 14176 is for improperly crimped pedal terminals, printed as free with no end date. → Route 1.

"A GM car or truck with P2138 after rain, a leak or a wet floor." GM's 07-06-04-019E and 019F print water in the instrument-panel-to-body harness connector and no pedal. → Route 2.

"A 2015-2017 F-150 or 2017 F-Super Duty with a wrench light, loss of pedal response and P2138." Ford's SSM 46829 and 46880 print the pedal harness routed wrongly behind the brake booster. → Route 2.

"A 2016-2019 Mercedes-Benz E-Class or GLC, limp mode and an ESP warning." Mercedes prints possible contact resistance in the pedal signal lines and extended the pedal wiring warranty on certain cars. → Routes 1 and 2.

"A Subaru, a Toyota or a Hyundai, a car with P2135, or any car no paper covers." For P2135 the papers point at the throttle side (a throttle-body procedure, a software flash or, in Ford's case, a harness near the throttle body): → Route 5. For P2138 on a car none of our papers covers (Subaru has 64 complaints and no paper at all; the Honda, Jeep and Nissan papers cover only the models they name): run the VIN at a dealer, check the plug, harness and floor, then ask for the test before a pedal. → Routes 1, 2 and 4.

The P2138 price ladder, from the bottom up

Our guide figures are typical independent-shop prices; owners' figures include dealer bills and quotes, so the owner range for a pedal reaches $900. Read the ladder as the reason to work cheap-first: the expensive mistake is paying for the pedal, the throttle body and the computer in turn, on a guess.

The five P2138 routes, cheapest first

The code is a statement about two signals. Each route below is a place the signals can be lost or distorted, ordered by what it costs to rule out. Owner counts come from the 915 relevant complaints; "came back" means the owner says the same light, code or symptom returned or the repair did not hold. The pedal is the most common stated end in the complaints (237) but sits fourth, because it costs more to test than a plug, a coverage lookup or a software question. Complaints come mostly from owners whose trouble did not end, so none of these shares is a forecast for your car.

Route 1 · A free repair: recall, special coverage or warranty extension — $0 when it applies

What it is. The maker has printed a possible cause on certain cars and pays for the repair where your VIN is covered. Recall 14176 is an inspection whether or not the light is on; the coverages pay when the condition shows up.

What the documents say. 🟢 GM's emissions recall 14176 for the 2014 Cadillac ATS: "Some of these vehicles have a condition in which the electrical terminals are not properly crimped to the Accelerator Pedal Position (APP) circuits at the engine harness side of an inline electrical connector." The repair is a dealer inspection of the terminals, soldered or replaced as required, and the paper says "Dealers are to service all vehicles subject to this recall at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward." 🟢 GM's special coverage N182188250 for 2016-2018 Malibu, 2017-2018 LaCrosse and 2018 Regal: "This special coverage covers the condition described above for a period of 10 years or 150,000 miles" from first service; the pedal is replaced only if diagnostics lead there, and for the Malibu with GM engine code LFV the engine harness is inspected for contact with the heater inlet hose clamp. 🟢 Mercedes-Benz extended the pedal wiring harness and connector warranty on certain 2016-2019 E-Class and GLC to 10 years or 120,000 miles; the letter says contact resistance in the pedal signal lines could put the engine in limp home mode, and may reimburse earlier repairs paid after the original warranty ended, with receipts, possibly limited to what an authorized dealer would have charged, for Mercedes-Benz parts only, and repairs at other shops might not be reimbursed. 🟢 GM's older special coverage 14636 and Jaguar Land Rover's program Q442 have closed by their printed terms; the coverage file below does the arithmetic.

What the owners report. 176 of the 915 complaints mention a recall, a campaign, a bulletin or a coverage, or being told there is none (19%), and 57 of those 176 say the problem came back. On 2016-2018 Malibu (hybrids included) there are 150 relevant complaints, 49 mention P2138 and 58 end at a pedal; 42 of the 150 were received in 2019. A 2016 Malibu owner wrote in January 2019 that "THE GAS PEDAL AND SENSOR ARE ON A NATIONAL BACKORDER" and that the owner would have to pay for the repair and the rental car; the first version of GM's coverage paper is dated August 2019. A 2011 Malibu owner with P2135 was told coverage 14582A was open "BUT THEY SAID MY VIN WAS NOT COVERED BY THAT PROGRAM".

The cheap cause that gets skipped. The lookup itself. A recall or coverage costs a phone call, and only the VIN answers the question.

Fix it yourself. The lookup only. nhtsa.gov/recalls lists safety recalls, and the papers call 14176 an emissions recall and N182188250 a special coverage, so the VIN lookup may show nothing (see the coverage file below); the dealer, with your VIN, is the real lookup. (Our advice: do not wait for a letter.)

At the shop — say this: "Please run my VIN for GM recall 14176 and special coverage N182188250 (or Mercedes' pedal wiring harness extension), tell me whether I am inside the years and miles, and write the answer on the repair order before any part is ordered." For other makes, say this: "Please run my VIN for any recall, special coverage or warranty extension for the accelerator pedal or its wiring, and write the answer on the repair order."

Route 2 · The plug, the water and the wire — $0 yourself, $150 to $500 at a shop

What it is. The two pedal signals travel through a connector under the dash, a harness and a plug at the pedal. Water, a bent terminal, a poor crimp, a pinch or a rub can change one signal and not the other.

What the documents say. 🟢 GM's water bulletin prints a possible cause and tells the shop to look for a leak and repair it if found, and to inspect the connector's terminals for corrosion. 🟢 GM's pedal-code information for 2007-2014 trucks and SUVs says "In most cases, this concern is very intermittent so the technician may not be able to get the DTC(s) to reset so they can perform step by step diagnosis." and, when the steps do not isolate the cause, "recrimp all of the APP circuit terminals at the APP sensor and ECM connectors using the correct terminal crimp tools". 🟢 GM's note for 2016 trucks lists P2138 with five-volt reference codes and says to inspect the wiring harness near the left IP junction block if the published diagnostics are inconclusive. 🟢 Ford's two messages say the loss of pedal response may be caused by the pedal harness "being improperly routed behind the brake booster to brake pedal bracket." 🟢 Mercedes-Benz says "The fault entry may have been caused by resistance at contacts." and, when all test steps find no faulty component, replaces the connector and feed line to the pedal sensor with a harness repair kit, and asks for a case with photos after a second failed repair.

What the owners report. 56 of the 915 complaints end at a wire, a plug or a connector, and 33 of them say it came back (59%), more than the pedal (41%) or the throttle (36%); among the 230 that mention P2138, 16 end here. Looking at the plug and the wire is the cheapest test ($0), but a repair only holds if the cause is fixed too, such as the leak or the harness routing (our advice: ask the shop what let the water in, not only what it cleaned). A 2008 Ram 3500 owner lists a pedal replaced, then "THEY RE-CRIMPED THE PLUG ON THE PEDAL SENSOR AND THE C130 CONNECTOR UNDER THE HOOD. THAT LASTED ABOUT A MONTH AND A HALF."

The cheap cause that gets skipped. Water, and a plug that was never wrong. A Scion iQ owner (listed as a 2012; the owner writes 2013) who unplugged and replugged the pedal writes "Plugged the pedal back in and all was good then." and that the problem returned years later; one owner's story, not a repair. GM's bulletin names water in the connector as a possible cause; in our reading, a connector cleaned without finding the leak is a repair waiting to fail.

Fix it yourself. Only the looking: the pedal plug seated and clicked, the harness near the pedal for a pinch, the floor and kick panel for water. (Our advice: leave terminal probing and recrimping to a shop; GM's own paper says recrimping needs the correct crimp tools.) A wiring repair is a ⚪ $150 to $500 shop job in our P0103 guide.

At the shop — say this: "Please test the pedal circuits while moving the harness, check the instrument-panel connector for water and the terminals for corrosion, and tell me the bulletin number you followed. Please write the readings on the invoice."

Route 3 · Software and relearn — $0 to $200 for a flash, free under a program

What it is. The wiring is sound, but the computer's software sets or keeps a code, or a part was changed and the computer was never taught the new one.

What the documents say. 🟢 Mazda's service alert says "Check Engine light (with DTCs P0101, P061B, P2122, P2138) may illuminate after PCM reprogramming due to a mislogic detection in the PCM calibration, available in the current IDS version 103.03." on 2013-2015 CX-5, and the fix is to go back to version 103.00 and reflash. 🟢 Nissan's 2020-2021 Frontier bulletin reprograms for P0223, P0507 and/or P2135 when "There are no drivability concerns." and requires "Throttle Valve Closed Position, Idle Air Volume Learning, Accelerator Closed Position and DTC Erase" afterwards. 🟢 GM's bulletin for P2135 on 2008-2011 trucks and SUVs says "ALL Model Year 2008-2011 vehicles MUST have the engine control module (ECM) reprogrammed with the latest software calibration" after the throttle sensor cover is replaced. 🟢 Chrysler's flashes list throttle position sensor circuit codes and say "Reprogram the PCM with the latest software." None of the Nissan, Lexus, GM or Chrysler software papers above prints P2138; only Mazda's alert does.

What the owners report. Only 10 of the 915 complaints end at software or a computer, and 7 of them say it came back. A 2016 Wrangler owner says the dealer "RELEARNED THE PEDAL POSITION SENSOR WITH A FIRMWARE REBOOT" and that it did not fix the problem; two 2006 Kia Amanti owners report a computer replaced at $2,000 or more.

The cheap cause that gets skipped. An update that already exists, and the relearn after a part change. Mazda's alert shows software can cause the code as well as cure it; Nissan makes the relearn part of the job.

Fix it yourself. Not honestly. Flash tools, relearn routines and the battery support the papers ask for (Chrysler keeps the battery at 13.2 to 13.5 volts) belong to the shop. (Our advice: do not accept a computer replacement on a P2138 without the maker's written approval; no paper we read prints one.)

At the shop — say this: "Is my software current for my VIN, was there a flash or relearn after the last pedal or throttle part, and what does the maker's bulletin list say about my code?"

Route 4 · The pedal assembly — $100 to $400

What it is. The sensor inside the pedal, or the pedal's own plug, really is bad.

What the documents say. 🟢 GM's special coverage 14636 says "Dealers are to replace the Accelerator Pedal Assembly." after the dealer verifies that it needs replacing (if not, nothing further is covered), with the note that "The new replacement pedal (1) has a redesigned mounting bracket, which is shaped differently than the original pedal (2)." The cause is a broken solder connection inside the pedal sensor, on 2009 LaCrosse and Allure and 2009-2011 Impala. 🟢 GM's N182188250 prints a pedal for the Malibu, LaCrosse and Regal when diagnostics lead there, at 0.3 hour of labor. 🟢 GM's 16-NA-012 for 2010-2015 Equinox and Terrain says "Replace Accelerator Pedal Position (APP) Sensor assembly part number 25798449, and APP harness part number 13584094. Reroute the harness." only when the connector shows damage. 🟢 Kia's SC202 replaces the accelerator pedal assembly on 2021 Sorento built September 9 to December 3, 2020, for a higher-than-expected idle in Park; the paper names no code.

What the owners report. 237 of the 915 complaints end at a pedal (26%), and 97 of them say it came back (41%). 41 describe a stall and 191 describe reduced power. 108 of the 237 are Chevrolets and 64 are Malibus. A 2016 Malibu owner has replaced the pedal sensor three times by the owner's count. A 2017 Malibu owner who replaced the pedal at home reports "I replaced the pedal myself at a cost of $114.00." and, in December 2023, being told by GM customer service that the program expired in 2020; the printed terms are 10 years or 150,000 miles from first service, and 2020 is the printed date for reimbursement requests, so ask for the answer in writing with the terms in your hand.

The cheap cause that gets skipped. The plug and the coverage. Chrysler's tip warns that P2122 and P2127 set when the pedal connector is unplugged; GM's coverage pays for the pedal when diagnostics lead there. Replacing the pedal on a wet connector gives a new pedal and the same code.

Fix it yourself. Sometimes, where the pedal bolts on and the codes have already pointed there. The $114 owner above did it; Kia's own campaign paper starts with the battery's negative terminal disconnected, and torques the pedal to 6.5 to 10.1 lb-ft. (Our advice: do it only after the plug, harness and VIN checks, because ⚪ $100 to $400 for a pedal assembly in our won't-accelerate guide is cheap next to a second pedal.)

At the shop — say this: "Which test showed the pedal and not its plug or harness? Is the part a maker part, does it carry a warranty, and is my car under any coverage that pays for it?"

Route 5 · The throttle body or its sensor, and the computer as a last resort — $300 to $800 for a throttle body in our guide, up to $1,500 in owner reports, $1,009 to $2,000 for a computer in owner reports

What it is. For P2135, and for pedal codes that survive every check above, the fault is the throttle's own two position sensors or, at the very end, the computer. This route is the P2135 side; the throttle motor is another fault.

What the documents say. 🟢 GM's bulletins for P2135 say "Attention: If a vehicle is encountered with this condition, DO NOT replace the throttle body. Instead follow this procedure below." The procedure replaces the throttle position sensor cover and checks the scan tool parameter while the pedal is pressed: "If TP Sensor 1 and 2 Agree/Disagree parameter displays Disagree, replace the throttle body assembly." 🟢 GM's special coverage 14582A starts with "With a scan tool, verify that DTC P2135, P0121 OR P0221 is set as Current or in History." and replaces the throttle body on Bosch-equipped cars and fits a sensor kit on Hitachi ones. 🟢 Mazda's Tribute bulletin (built June 22 to October 15, 2009) says "Replace the Throttle Body Assembly per the Workshop Manual" for P2135. 🟢 Ford's 2012-2014 Focus 2.0L bulletin TSB 18-2062 (built on or before February 4, 2014 with an automatic or February 19, 2014 with a manual transmission) lists P2127 and P2135 among 17 codes and tells the technician to inspect "the engine harness for chafing against the intake manifold, near the throttle body." GM's special coverage 11273A for 2008-2011 V8 trucks and SUVs, a scanned paper, is for P2135 and has run out.

What the owners report. 81 of the 915 complaints end at a throttle part (9%), and 29 say it came back (36%); 78 mention P2135, of which 15 end at a throttle part, 4 at a pedal and 3 at a wire. A 2008 Kia Sedona owner replaced a $40 throttle position sensor (the maker first offered only a $350 throttle body) and wrote "I REPLACED THE PART AND IT IS STILL DOING THE SAME THING". Two 2003 Tacoma owners were offered a whole throttle body at $1,200 and $1,400, and 3 owners report a computer replaced for $1,009 to $2,000.

The cheap cause that gets skipped. The harness near the throttle body and the relearn. Ford's bulletin has the technician look for chafing at the intake manifold; Mazda's Mazda6 paper finds electrical noise after a new throttle body. Both are cheaper than a second throttle body.

Fix it yourself. Cleaning and fitting a throttle body is a driveway job on some engines, but this route starts with a scan-tool reading of the two sensors that a code reader does not give. (Our advice: ask for the Agree or Disagree reading before the part, and for the relearn after it. Our throttle body replacement cost guide carries the prices and the relearn.)

At the shop — say this: "Did the two throttle position sensors disagree on the scan tool, or is this a code only? Is the harness near the throttle body checked, and is the throttle relearn included?" For a computer, say this: "Is my engine computer still under any warranty, and what did the maker's support say, in writing?"

The coverage file: which recalls and coverages run in September 2026

Most papers above are repair instructions, not coverage. The status column is our computation from the printed terms, as of September 2026, and it is not a promise from any maker.

These emissions recalls and special coverages did not show up in the safety-recall lookup. We found no NHTSA safety campaign under 14176, N182188250, 14636 or 14582A in NHTSA's recall file with reports through October 1, 2026; GM's paper calls 14176 an emissions recall. nhtsa.gov/recalls may therefore show nothing; the dealer, with your VIN, is the lookup.

What 1,182 complaints show

How we went through them. We read every complaint in NHTSA's file received from January 2015 through early October 2026 that names P2138 or a sister code, or describes the pedal or throttle position sensor in owners' words with a fault: 1,182 in all. Each was sorted twice, independently, by the same written rules, and the two sortings matched on the main category in 93%. We publish the sorting rules and how we did it; the full counts are in the methodology note. 915 describe a pedal or throttle position-signal fault on the owner's car; 267 do not.

Is it the pedal? Of the 915, 237 end at a pedal (26%), and 97 of those say the problem came back or the repair did not hold (41%); the same share is 59% for wires and connectors (33 of 56), 36% for throttle parts (29 of 81) and 30% where no cause is named (138 of 466).

Which cars. Chevrolet is 393 of the 915 (43%), Subaru 89, Ford 75, GMC 42, Hyundai 36 and Jeep 33. The Malibu and Malibu Hybrid together are 187 (20%), the Impala 78 and the Subaru Outback 64. Fourteen are motorcycles: ten Harley-Davidson and one each Triumph, Yamaha, Indian and BMW.

What happened. 738 describe reduced power or a pedal that did not command the engine (81%), 151 a stall or a loss of drive (17%), 176 a recall, campaign, bulletin or coverage, or being told there is none (19%) and 328 a return of the problem (36%). In NHTSA's own fields, 12 of the 915 are marked as a crash, 2 as a fire, 4 with an injury and 23 as a tow, and one is marked with a death.

Is a reduced-power P2138 dangerous, and does a new pedal stop it? PulsCar sorted, twice and independently, the 1,182 complaints in NHTSA's file from 2015 to early October 2026 that name P2138 or a sister code or describe the fault: 915 describe it on the owner's car, 738 as reduced power or no response to the pedal and 151 as a stall or a loss of drive, with 12 marked as a crash, 4 with an injury and 23 as a tow. Where a complaint ends at a pedal, 97 of 237 say the problem returned; at a wire or connector 33 of 56; at a throttle part 29 of 81. None of the maker documents about P2138 says to stop driving, but the complaints show what the fault can do at highway speed. Our rule: reduced power, a stall, a car that will not accelerate or a flashing light is a tow.

The complaints that mention P2138 or a sister code themselves

230 of the 915 mention P2138 (25%): 172 end with no cause named (75%), 25 at a pedal, 16 at a wire or connector, 10 checked and cleared, 4 at another cause and 3 at a throttle part; 200 describe reduced power (87%) and 23 a stall. Chevrolet is 108 of them (Malibu 54, Silverado 1500 11, Impala 9, Sonic 6) and Subaru 64 (Outback 48, Legacy 7, Forester 5; 53 are model years 2005 or 2006). Buick is 12 and GMC 11. 21 also mention a pedal circuit code; across all 915, 43 mention P2122, P2123, P2127 or P2128 (P2122 28, P2127 13, P2128 7, P2123 1; some mention more than one). Only one mentions both P2138 and P2135. Many of the Subaru complaints that mention P2138 (29 of 64; 34 of all 89 Subaru complaints) describe a pattern no paper we read explains: reduced power with a flashing cruise-control light.

78 mention P2135 (the throttle side): 48 name no cause, 15 end at a throttle part, 5 are checked and cleared, 4 end at a pedal, 3 at a wire and 3 at another cause; 65 describe reduced power and 18 a stall; 28 mention a recall or coverage (36%). Chevrolet is 44 of the 78. A pedal code is not a throttle code: where owners name P2138 the end is a pedal or wire in 41 of 230, where they name P2135 it is a throttle part in 15 of 78.

What owners say they paid

Of the 915 complaints, 70 state a dollar figure tied to the repair: 75 figures (25 bills, 23 amounts paid, 21 quotes, 4 offers, 2 with no stated status) in the groups pedal 26, throttle 21, several parts in one figure or one part not named 14, diagnostic fee 9, computer 3 and wiring 2. They are what owners wrote, not audited invoices, and we publish them with NHTSA complaint numbers; one wiring figure is in Canadian dollars. The ladder above shows each group's range and median.

How much does it cost to fix P2138 in 2026, and when is the pedal the wrong first purchase? PulsCar took every dollar figure in the 915 relevant complaints that meets one written inclusion rule: 75 figures in 70 complaints, 48 of them bills or amounts paid. A pedal runs $35 to $900 with a median of $345 across 26 figures, a throttle part $40 to $1,500 with a median of $500, diagnostic fees $100 to $212 and a computer $1,009 to $2,000, while several parts in one figure reach a $4,027.91 quote. Our repair guides carry $100 to $400 for a pedal assembly, $150 to $500 for wiring and $300 to $800 for a throttle body. A recall or coverage costs $0 where it applies, so the VIN and the plug come before any part.

Why P2138 comes back after a repair

The signal was never the pedal's fault. A wet connector or a pinched harness gives the same code with a new pedal in the car; that is why the documents put the plug and the harness before the part. A part was changed and never relearned. Nissan and GM print relearns. The cause is intermittent. GM's pedal-code note says that in most cases the concern is very intermittent and the code may not reset for diagnosis. The fix was a clear. 37 complaints end with nothing found or only a cleared code. In all, 328 of the 915 say the same light, code or symptom returned or the repair did not hold, and 7 of the 10 that ended at software say it did.

Can you drive with P2138?

It depends on how the car behaves, and this is our rule, not any maker's: none of the papers we read about P2138 says to stop driving. A steady light with normal driving and no loss of power: a shop within days, avoiding highways and heavy traffic until then. If the car has gone into reduced power, stalled, will not accelerate, or the check engine light is flashing, do not drive it to the shop: have it towed. If power drops while you are on the road (our advice): turn on the hazard lights, signal, move out of the traffic lane to a safe place as soon as it is safe, and call for the tow. GM's coverage paper says the pedal still functions in reduced power, and Mercedes' letter says brake, steering and ABS keep normal effectiveness while ESP, brake assist and PRE-SAFE may be unavailable (GM's ATS recall letter also prints traction and stability control disabled), but neither says the car keeps moving at speed: 151 of 915 complaints describe a stall or a loss of drive; one of them, received in July 2025, describes a 2016 Malibu that lost power at highway speed, slowed from 55 to 20 mph, stalled and was hit by an SUV, with a death reported (NHTSA's field marks one death; we cannot verify the account). A car that drops to 20 mph in fast traffic is its own warning.

Should you buy a used car with a P2138 history?

Ask what was found, not what was replaced: in the file, 97 of the 237 complaints that end at a pedal say the problem returned, so a pedal on the invoice is not the end of the story. Ask for the invoice that names the test, have a dealer run the VIN for 14176, N182188250 and any extension, and before you pay have the car scanned, driven through a full warm-up and scanned again. A 2016-2018 Malibu, 2017-2018 LaCrosse or 2018 Regal bought today may still be inside GM's coverage if it was first in service less than 10 years ago.

Clearing P2138 before an inspection

A cleared code returns if the cause is a wet connector or a pinched harness, and many inspections need the car's self-checks to have run again before the car can pass; ask the station. Fix first, drive several normal trips, then test. 🟢 Nissan's Frontier paper makes the relearn part of the job: "When reprogramming is complete, you will be required to perform Throttle Valve Closed Position, Idle Air Volume Learning, Accelerator Closed Position and DTC Erase." Our guide on how to reset a check engine light covers the mechanics.

What the papers tell a shop to do with P2138, checkpoint by checkpoint

Checkpoint 1 — the code. GM: current or in history. Checkpoint 2 — water. GM: the instrument-panel connector, the leak. Checkpoint 3 — the harness. Ford: routing behind the brake booster; GM: pinch points. Checkpoint 4 — plug and terminals. Mercedes: contact resistance; GM: crimps. Checkpoint 5 — software and coverage. Mazda: the software level; GM and Mercedes: the VIN. Checkpoint 6 — the part. Only then the pedal, and the relearn the maker prints.

Three P2138 traps

Trap 1 · Buying the pedal from the code. The code does not say which part is wrong. GM's coverage pays for a pedal only when diagnostics lead there, Mercedes says that when all test steps find no faulty component, the repair is the harness kit and the pedal sensor is not to be replaced, and Chrysler asks for active codes first.

Trap 2 · A cleared code or a quiet week taken as a repair. GM's pedal-code note says that in most cases the concern is very intermittent; 37 complaints end with nothing found or only a cleared code, and 138 of the 466 with no cause say it returned.

Trap 3 · A coverage nobody asked about. 14176 is free with no end date, N182188250 runs 10 years or 150,000 miles from first service, and neither showed up in NHTSA's safety-recall file. Ask by number before you pay for a part.

The P2138 plan: 10 minutes, today, this week

Today (10 minutes). Key off, look at the pedal plug and harness, check the floor for water, read the code (a parts store will read it free), and write down the mileage and the date the car was first sold. Today (VIN). Ask a dealer for recalls and coverage by number. This week. If the light is still on or comes back, pay for one diagnosis, ask for the test that separates the pedal from its plug and harness, and for the bulletin number. If the car has gone into reduced power, stalled, will not accelerate, or the check engine light is flashing, do not drive it to the shop: have it towed. Skip the week.

These are composite scenarios, not individual customers; the dollar figures are ranges and single owner reports from the file. A 2017 Malibu shows Engine Power Reduced and P2138, and the shop quotes a pedal: the owner asks first for GM's special coverage N182188250 by number, since a car first in service less than 10 years ago, under 150,000 miles and on GM's VIN list is still covered, and the pedal is replaced only if diagnostics lead there; one owner of a 2017 Malibu with P2122 who replaced the pedal at home paid $114 and was told later that the program had expired. A truck throws P2138 after rain with a wet floor: GM's 07-06-04-019E and F print water in the instrument-panel connector, and a wiring repair is $150 to $500 in our guides. A 2006 Outback shows P2138 with a flashing cruise light: there is no Subaru paper, so the order is the plug and harness at $0, one diagnosis (median $150 in owner reports), then a pedal (median $345).

Sources and documents

Primary documents only. Claims marked 🟢 rest on one of the items below; claims marked ⚪ are shop-price estimates carried from PulsCar's repair guides.

1. General Motors: emissions recall 14176, 14176A, 14176B and the owner letter; special coverage 14636 and its owner letter; special coverage N182188250 Revision 00, Revision 01 and Revision 02; special coverage 14582A and 11273A; bulletins 07-06-04-019E, 07-06-04-019F, 11-06-04-007C, 12-06-04-003 and 16-NA-012; preliminary information PIP3783D and PIP5344; service updates 22860, 16016 and 18038.
2. Ford: SSM 46829, SSM 46880, SSM 47432, SSM 47656, SSM 50116, SSM 50245, SSM 54736, SSM 55072 and TSB 18-2062.
3. Stellantis: tech tips 9003413 and 9004225; flashes 18-045-16 Rev. A and 18-090-16 Rev. A.
4. Jaguar Land Rover: SGI14-51, SGI14-52, Q431, Q442 and SSM72100.
5. Mercedes-Benz, Honda, Mazda, Nissan, Lexus, Kia: Mercedes LI54.18-P-067550 and the warranty extension letter; Honda dealer message; Mazda SA-001347, 01-007/13 and 01-015/13, second issue; Nissan NTB21-080; Lexus L-SB-0042-19; Kia SC202 and its questions and answers; Triumph bulletin, a motorcycle paper counted only in the file totals.
6. PulsCar analysis of NHTSA public data, October 2026: 1,182 complaints about pedal and throttle position signals, each sorted twice by the same written rules; owner-reported amounts; the document list with reading status. Complaints, amounts, documents, the sorting rules and how we did it (CC BY 4.0).

For the neighbouring pages: a car that won't accelerate, a car that hesitates when accelerating, a car that stalls while driving, what a check engine light means, throttle body replacement cost, how to reset a check engine light and the check-engine code index.

PulsCar does not diagnose a pedal or throttle position-signal fault from the sound of the engine. For P2138, the test of the plug and harness is the evidence.

Methodology. The complaint set is every complaint in NHTSA's file received from January 2015 to early October 2026 that names P2138 or a sister code (P2135 to P2140) or a pedal-circuit code in any spelling we searched, or describes the pedal or throttle position sensor in owners' words with a word about a fault, a repair or a symptom, in two batches (971 from the first search and 211 more from a second search limited by a written scope note): 1,182 in all. Every complaint was sorted twice, independently, by the same written rules, fixed before each batch was sorted; the two sortings matched on the category in 93% of them (1,097 of 1,182) and on the reduced-power, stall, recall and came-back marks in 96% to 99%; in 179 complaints at least one of the five marks differed, and every disagreement was settled by a written rule, and a final check against the whole texts changed 81 rows (one cause and 80 reduced-power or stall marks), 57 of them rows on which both sortings had agreed. 915 describe a pedal or throttle position-signal fault on the owner's car and 267 do not. About 2,080 complaints found by the second search that blame only a throttle body or its motor were left out. Counts are of complaints, not cars, and nothing here is a failure rate. The document set is 231 NHTSA index entries, of which 52 had no PDF and were not used; 181 files were downloaded, one would not open, and 22 of the 180 readable files carry exactly the same text as another file, leaving 158 distinct documents. We read 111 in full and compared the other 69 files (47 distinct documents and 22 exact copies) with them line by line; one scanned paper was read from page images. Coverage status "as of September 2026" is our computation from printed terms. Amounts follow one written inclusion rule; one figure is in Canadian dollars.

Prices verified July to October 2026 in the repair guides they are carried from and in the owner reports above, and reviewed quarterly. Technical documents verified October 2026: the 158 distinct documents in our published file, of which 111 were read in full.

Had P2138 cleared by a plug, a wire, a software update or a coverage, or a pedal replaced for nothing? Email [email protected] with the vehicle, mileage and outcome.