P0521 and P0520 Codes: Low Oil Pressure or Bad Sensor?

P0520 and P0521 are codes about a signal, not a part. The engine computer reads the oil pressure from a sensor or switch screwed into the engine, and these codes say the signal is wrong or does not fit. P0520, printed by Chrysler as "P0520- Engine Oil Pressure Sensor Circuit", says the circuit failed a check; P0521, printed by GM and Chrysler as "Engine Oil Pressure Sensor Performance", says the reading does not agree with what the computer expects. Neither says which side is wrong: a sensor that lies, a wire or connector, or an engine that has really lost pressure.

This page answers three questions: is the oil pressure really low or is the sensor lying; can I drive; what does it cost. The general lamp guide is low oil pressure warning. P0522 and P0523 are the low and high voltage versions of the circuit code and P0524 is "oil pressure too low" (standard names; the papers word them differently). Related codes, named here only as the papers print them, are the oil pressure control-valve codes P06DA, P06DD and P06DE and Chrysler's maker-specific P1524 (oil pressure out of range). Fuel in the oil, which can set P0521 on some GM engines, is in the P0172 guide.

The headline. Few of the papers that print these codes end at the sensor. Grouped into families (a bulletin and its revisions count once), 46 passenger-vehicle families print one of P0520 to P0524 (a Volvo heavy-truck paper that replaces the sensor for P0524 is not counted): 3 end at a sensor or switch, 15 at an oil pump, valve or another part of the oil circuit, 10 at software, 6 at wiring, 6 at the oil or its filter, 1 at engine wear, and 5 name no cause. A lamp is not always a false alarm: on an engine that has lost oil pressure, it is the last warning before the damage.

What the page rests on. The US safety regulator NHTSA files carmakers' service papers and owner complaints. Of all complaints received from January 2015 through early October 2026, only 56 spell out P0520, P0521, P0522, P0523 or P0524 (two write only "code 520"; two Toyotas write extended forms such as P05202A); the 3,010 we sorted are the ones that describe an oil pressure warning, sensor, switch or gauge event in the owner's words. 2,748 describe an engine oil pressure event on the owner's own car and 262 do not. Read every count as "complaints describing an oil pressure event", never "P0521 complaints". Counts are complaints, not cars; nothing is a failure rate.

Is a P0521 or P0520 code a failing oil pressure sensor, and is it safe to keep driving? PulsCar sorted 3,010 federal owner complaints about oil pressure warnings and read the carmaker papers that print the codes. Of 46 families of passenger-vehicle papers that print P0520 to P0524, 3 end at a sensor or switch, 15 at an oil pump or oil-circuit part, 10 at software, 6 at wiring, 6 at the oil or its filter, 1 at engine wear, and 5 name no cause. In the complaints, 228 end at a sensor or switch (8%), 399 at oil level, leaks or filters (15%), 153 at a pump or oil circuit (6%) and 719 at engine damage (26%), while 39% state no cause. A red lamp, a zero gauge, an engine noise or a pressure-too-low code (P0524 in any form) means stop and tow; a bare P0520 or P0521 needs a mechanical pressure reading before any part is bought.

🟢 marks a claim resting on a document in the Sources section; ⚪ marks a shop-price estimate from our repair guides. Every complaint count comes from the 3,010 complaints we sorted; owner-reported figures are published with NHTSA complaint numbers, and the documents are listed. Mechanical gauge: a gauge screwed into the engine in place of the sensor.

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 P0520 and P0521 say: the signal and the engine disagree

The computer asks the sensor for a number and compares it with what the engine should be doing. P0520 says the circuit failed an electrical check; P0521 says the number is possible but does not fit. The cause can be a sensor that measures wrongly, a wire, a pump or valve that really delivers less, thin or low oil, or software that judges the wrong thing. The code cannot tell these apart, and neither can a driver. 🟢 Audi prints its version as "P052100: Engine Oil Pressure Sensor/Switch "A", Range/Performance".

The codes are not a measurement of how bad the pressure is. 🟢 Porsche says the Macan S, GTS and Turbo condition behind P052100 (an over-sensitive trigger) is "not harmful to the engine", while a GM bulletin on the same P0521 for 6.0L trucks says the cause is a sticking relief valve or a damaged main bearing. Same code, opposite stakes. That is why the first rule here is the lamp and the noise, not the code. In the papers, P0520 appears in one family (Chrysler's 18-034-14) and P05202A in another (Toyota's T-SB-0104-21), P0521 in 27 (19 of them GM), P0524 in 17 (one as Toyota's P052477), and P0522 or P0523 in 5; a family can print several.

First: which code, which sensor, which maker

The same number means different things in different papers. Only codes the papers print are here.

Two things the makers call normal. 🟢 GM, 2010-2015 Cadillac CTS and Chevrolet Camaro 3.6L: a gauge reading of "up to 110 psi (758 kpa.) of oil pressure" at a cold start (and under some acceleration) returns to about 60 psi as the engine warms, so "no repair attempts or parts should be replaced" (a high reading; the paper adds that a warm engine can read as low as 20-25 psi, and says nothing about a low-pressure lamp). GM, 2014-2018 Silverado and Sierra 1500 and 2015-2018 SUVs: a gauge that jumps between about 40 and 60 psi three times in the first minutes is the two-stage pump's test routine; about 60 psi above 3,700 rpm is its high-pressure stage.

The maker atlas: papers on oil pressure codes and warnings, and what they blame

Bulletin numbers are linked to NHTSA's PDF. Most print P0520 to P0524; the others (among them Ford 46253 and 49200, Mazda 01-014/15, Subaru, Nissan, Kia WTY026, Honda, Audi 2041093/3, Porsche 76/16, BMW, McLaren, GM PIP5844, Chrysler S2109000001) are about the same lamp or switch without them.

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

• Rolls-Royce Cullinan (A 02 2021 03, an earth-connection campaign; no code printed): 🟢 loose engine ground connections can lead to "oil pressure sensor damage." The shop follows the sensor-replacement instructions only to reach the ground connections: "DO NOT replace sensor".
• Audi RS 3, 2022 (2068121/1): 🟢 "Do not replace any components for this condition, since this will not resolve the customer's concern." Its successor 2067756/2: "Replacing parts or attempting repairs will not correct the DTC."
• Ford (SSM 47072): 🟢 "If unable to determine root cause, do not attempt any repairs." Ford (SSM 46526): replace the sensor "If evidence of liquid contamination is found", and "Do NOT use di-electric grease in the sensor electrical connector."
• Mazda (01-008/17): 🟢 after a pressure reading: "NOTE:There is no need to replace the oil filter or oil pan."
• BMW (SI B11 22 16): 🟢 a stop message on a new car with under 60 miles and a one-time fault: "A parts exchange is not necessary and does not provide a solution."

The 10-minute check

Do this only if the red lamp stayed off while driving and no P0524 is stored, or after the tow. If the red lamp is lit, you are not doing a check, you are stopping.

1. Level, on level ground (2 minutes). Engine off for a few minutes, then the dipstick: between the marks, not above full. 🟢 GM's 6.0L bulletin 20-NA-161 starts here: "Remove the oil level indicator and confirm the oil level is at the full mark and not overfilled." Mazda asks its dealers: "Is it above MIN on the dipstick and in good condition using an OEM filter?" and, in its newest alert, to "Verify the oil level is correct and the proper oil weight is used." (SA-048-26) The grade is the one on the filler cap.

2. The last oil change (2 minutes). When, by whom, with which filter. A code or lamp that began right after a change points here before a sensor (Route 2).

3. The connector and the wires (2 minutes). Engine off and cool. Is the sensor's connector wet with oil or another liquid, is the harness intact? 🟢 Ford's paper names liquid contamination in the connector; GM's papers name a harness chafed on an air-conditioning line, a ground stud or an EGR gasket tab. Spray nothing into the connector.

4. Every code, with the freeze frame (2 minutes). 🟢 GM prints P0521 next to P06DD or P06DE in its pump and valve papers and next to P06DA in its newest wiring paper (PIP6125). Many parts stores read codes free; ask for the freeze frame.

5. Run the VIN (1 minute), at nhtsa.gov/recalls and with a dealer.

6. At a shop, a mechanical gauge reading. The step that separates the two stories, about $75 to $200 in our low oil pressure guide. The numbers the papers print are for one engine each; ask for the specification of yours. 🟢 Mazda's 2.0L and 2.5L (oil at 90 °C, 194 °F) wants 50 kPa (7 psi) or more at 650 rpm; GM's 1.2L turbo, "160 - 200 kPa (23.21 - 29.01 psi)" at idle with the oil at 80 to 100 °C (176 to 212 °F).

Six oil pressure code situations, and which is yours

"The red lamp is on, the gauge reads zero, the engine knocks, or a code says the pressure is too low (P0524 in any form)." Stop, switch off, tow. → Routes 4 and 5.

"P0520 on a 2013-2014 Jeep, Dodge, Chrysler or Ram (the bulletin's list), amber light only, engine fine." The part is cheap; owners report quotes of up to 4 hours of labor (the bulletin allows 0.3 to 1.8). → Route 3, and the coverage file below.

"P0521 with P06DD or P06DE on a GM truck, SUV or 1.2L turbo." A gauge first, then the pump or valve. → Route 4.

"The lamp or the code started right after an oil change." → Route 2.

"P0521 on a Buick Encore GX or Chevrolet Trailblazer that fails an emissions test, with no lamp, no noise and a normal gauge." → Route 1 (with a lamp or a noise, stop and tow; GM's later papers for the same 1.2L cover a wiring harness (PIP5826B) and, for unsold dealer stock only, a stuck pump (A202302140, ended April 2021)).

"A Kia 3.3L or a Mazda with a leaking switch, or a Subaru with a false lamp from a moist cap." → Route 3.

The oil pressure code price ladder, from the bottom up

How much does it cost to fix P0521 or P0520, and when is the sensor the wrong first purchase? PulsCar took every dollar figure in the 2,748 complaints that an owner tied to a repair, test or replacement for an oil pressure event: 314 figures in 251 complaints, 71 of them bills or amounts paid. Sensor or switch figures run $14 to $6,149 with a median of $425, oil and leak work $45 to $5,600 (median $1,400), pump and oil-circuit figures $12 to $11,000 (median $3,785) and engine figures $800 to $56,000 (median $7,707). Our guides carry $90 to $450 for a switch or sender installed, $75 to $200 for a mechanical pressure test and $400 to $3,000 for an oil pump. A recall or warranty repair costs $0, so the VIN, the oil level and a pressure reading come before a part.

The five oil pressure code routes, cheapest first

Each route is a place the lamp or the code can come from, ordered by what it costs to rule out, cheapest first; each route gives how common its ending is in the complaints. "Came back" means the owner says the same lamp, code or symptom returned. Engine damage is the most-named cause in the complaints (719 of 2,748, 26%) but sits last, because it costs the most and nothing can be done about it except stopping early. The sensor, the cheapest part to blame, is where 228 complaints end and where 3 of 46 families of papers end.

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

What it is. The maker has printed a fix that is a software update, a recall or a campaign: a lamp that comes on when nothing is wrong, or a code that will not clear. Only 14 of the 2,748 complaints end here (0.5%), yet 645 (23%) mention a recall, a bulletin, a campaign or special coverage, so ask before you pay.

What the documents say.

• 🟢 GM 2020-2023 Buick Encore GX and 2021-2023 Chevrolet Trailblazer: emission recall A222379711, 10,480 vehicles (the recall prints no engine): "The Engine Control Module (ECM) may not clear the permanent status of DTC P0521 (Engine Oil Pressure Sensor Performance)." The car "may not pass certain Emissions Inspection/Maintenance (I/M) tests"; the repair is a reprogram, free "regardless of mileage, age of vehicle, or ownership, from this time forward." Both the recall and the earlier service update A222379710 say "No parts are required for this repair."
• 🟢 Chrysler and Ram software updates for a wrong lamp: "Corrects a false oil pressure lamp illumination at key on (14&15 MY with 5.7L)." (18-103-16 Rev. B); "Correct a software issue with oil pressure light function at key-up." (2016 Ram 6.4L, 18-082-16); and for 2011 Ram cab-chassis trucks with the Cummins 6.7L, a flash with "Improvements To Prevent Unnecessary Malfunction Indicator Lamp (MIL) Illumination For:" P0524 among ten codes (18-013-13).
• 🟢 Audi RS 3, 2022 (2023 in the later paper): transport mode still active, or a warm restart when the oil pressure control valve is not switched by temperature, so the pressure is read as too high. The first paper said a software fix was still being tested and "Do not replace any components for this condition" (2068121/1); its successor prescribes an engine computer software update (2067756/2).
• 🟢 Mercedes engine 278: a stop message with the engine off, logged at 0 rpm. The order matters: "If the engine oil pressure is okay, flash the engine control unit with the latest engine control unit software and release vehicle to customer." (LI18.00-P-058770)

What the owners report. 13 of the 14 mention a recall or campaign and 5 say the problem came back. A 2021 Wrangler owner's dealer found by a diagnostic test that "the oil pressure was low" and could not repair it because the recall part was not yet available. Software cures a false alarm; it is no answer to a real one.

The cheap cause that gets skipped. The VIN lookup and the software level, and the question the Mercedes paper puts first: is the oil pressure okay?

Fix it yourself. The lookup only. nhtsa.gov/recalls lists safety recalls; campaigns, updates and emission recalls need a dealer and your VIN. A software update needs the maker's tool and a power supply that holds the voltage, which is shop work.

At the shop — say this: "Please run my VIN for any recall, campaign, special coverage or software update that names this code or this oil pressure message on this engine, and write the answer on the repair order before any part is ordered."

Route 2 · The oil, the filter and the leaks — $8 for a quart, $35 to $130 for a change, $10 to $2,500 for a leak

What it is. Pressure depends on enough clean oil of the right grade, a filter that passes it, and no way for it to leave. 399 of the 2,748 complaints end here (15%): 111 describe a stall, 15 engine damage, 33 say the problem came back. 167 mention an oil change, about 80 a leak, about 190 oil use or burning and 53 the dipstick (mention counts, not categories).

What the documents say.

• 🟢 GM, after an oil change: a wrong filter ("The PF48 oil filter will fit, but can cause the oil pressure to go low and DTC P0521 to set.", PIP5272A) or an empty one ("This issue was likely due to the engine oil filter not being pre-primed with engine oil before installation causing low or no oil pressure on initial start-up.", PIP5844, a P06DD paper for 1.3L and 2.7L turbo engines, whose fix is to clear the code and check it stays away).
• 🟢 Chrysler and Kia: P1524 after an AMSOIL-brand filter: "remove it and install an applicable MOPAR brand oil filter." (S2109000001) And a drain plug "stuck in the oil supply to the engine" after an oil change, which can set P0524 (Kia PS719).
• 🟢 Fuel and water in the oil: GM's short-trip bulletin (18-NA-246, covered in the P0172 guide) calls for an oil and filter change (and, on some years, a revised PCV valve or software); Toyota's T-SB-0104-21 blames "Moisture from blow-by gases" that freezes in the oil on short trips in extreme cold, and says it is not a warranty repair.
• 🟢 Oil use and leaks: GM's 16118, the 2012 Equinox and Terrain 2.4L, says the lamp or "Oil Pressure Low - Stop Engine" can come from piston ring wear.

What the owners report. A 2024 Santa Fe Hybrid owner writes that the dealer "failed to add engine oil, but recorded in the service invoice that it was added", that they drove 3 to 5 miles, and that the oil warning light did not come on: after any service, read the dipstick yourself. A 2020 Telluride owner, whose engine failed: "No oil warning light ever came on, and no low-oil warning, just a check engine light and the knocking."

The cheap cause that gets skipped. A dipstick read properly, then: when was the last oil change, by whom, with which filter?

Fix it yourself. Read the dipstick; if it is low, no red lamp is lit and no pressure-too-low code (P0524 in any form) is stored, top up with the grade on the filler cap (a quart is $8 to $15 in our low oil pressure guide), note the mileage and book a shop as in the amber case. With a lit lamp or such a code, do not top up and drive on: stop and tow as above. See the oil change guide, oil leaks, leak repair costs and blue smoke.

At the shop — say this: "The code or lamp started after an oil change, or the level is falling. Please check the level, the filter part number and how it was installed, and test for fuel in the oil and for leaks, and put the findings on the repair order before you sell me a sensor."

Route 3 · The sensor, the switch, its connector and the gauge — $90 to $450 installed in our guide; owners report a median of $425

What it is. The part that measures the pressure, or the wire that carries it, is bad, leaking or misreading; or the gauge shows what the engine does not. 258 complaints end here (9%): 228 at the sensor or switch, 19 at wiring, 11 at a gauge or cluster. Kia is 67 of the 228 sensor complaints (38 of them Sorento), Jeep 34 and Hyundai 33; 33 of the 228 (14%) say the problem came back.

What the documents say.

• 🟢 Chrysler P0520 (18-034-14): "This bulletin involves replacing the oil pressure sensor with a revised part." for 2013-2014 vehicles with engines built to March 12, 2014, 0.3 to 1.8 hours by model (18-034-14). The coverage wording is "Reimbursable within the provisions of the warranty."
• 🟢 Ford: liquid in the sensor connector on 2016-2017 F-150 3.5L and 5.0L, with the sensor replaced "If evidence of liquid contamination is found" (SSM 46526); "It is not required to replace the sensor" if it leaks at its threads on 2015-2016 Edge 2.0L, Mustang and F-150 5.0L and the 2016 Explorer 2.3L (SSM 46253); and a sensor design "not backwards compatible" that triggers P0521 after a short or long block replacement (SSM 50988).
• 🟢 Leaking or wet switches: Mazda, "ENGINE OIL SEEPAGE FROM ENGINE OIL PRESSURE SWITCH" in extreme cold (01-014/15); Subaru, a cap that lets in moisture and can "cause the oil pressure warning lamp to illuminate in error" (02-141-13R); and Kia, which extended warranty for certain 3.3L Sorento, Cadenza and Sedona models and notes that "a leaking Oil Pressure Switch (OPS) can be misdiagnosed as a rear main oil seal leak" (ENG237).
• 🟢 Gauge first: Porsche's order for a 911 GT3: change the oil and filter, check with the oil-pressure gauge, and "If the oil pressure measured using the oil-pressure gauge is OK ... Replace oil pressure sensor" (76/16).
• 🟢 Wiring: a harness rubbing on an air-conditioning line can make the gauges fluctuate and set a long list of codes, among them P0521 to P0523, on 2011-2013 Duramax trucks (PI0699B); a wire broken inside its insulation on 2023-2024 Equinox and Terrain 1.5L AWD (PIP6125); and high resistance in the engine wiring harness on 2020-2021 Encore GX and Trailblazer 1.2L (PIP5826B).

What the owners report. All 22 complaints that name P0520 are Jeep, Dodge or Chrysler, model years 2012 to 2014 (two write only "code 520" and two spell it with a letter O). Several describe a part that costs little and a job that does not: "THE OIL PRESSURE IS FINE AND YET I NEED TO REPLACE THIS $45 SWITCH WHICH WILL I'M BEING TOLD WILL TAKE 4 HOURS BY THE DEALERSHIP TO REPLACE." Another says the bulletin is "ONLY COVERDD UNDER WARRANTY." A Grand Cherokee owner: "I REPLACED THE OIL PRESSURE SENSOR AND THE ENGINE LIGHT CAME BACK ON A MONTH LATER WITH THE SAME CODE P0520."

The cheap cause that gets skipped. The connector and the leak. A sensor wet with oil, a connector with liquid in it or a harness rubbing costs a look; a new sensor in a wet connector brings the code back. And the reading few complaints mention: at least 15 of the 2,748 mention a mechanical or manual gauge, an oil pressure test or an oil pressure found fine; most do not say whether anyone measured.

Fix it yourself — the honest split. Look at the connector and wiggle it with the engine off and cool; check for oil around the sensor. Owners of the Jeeps say the sensor sits under the intake manifold ("THIS SENSOR IS LOCATED UNDER THE PLENUM AND INTAKE MANIFOLD"), and that is a shop job; a sensor in plain view on the block is within reach of someone with the tools. Ask where yours sits.

At the shop — say this: "What shows the sensor, not the pressure, is at fault? Please give me a mechanical gauge reading at idle and at 2,000 rpm on the repair order, check the connector and harness, and tell me which bulletin covers this engine before you replace it."

Route 4 · The pump and the oil circuit — owners report a median of $3,785; our guide $400 to $3,000

What it is. The oil is there but the engine is not getting it at full pressure: a relief valve that sticks, an oil control valve that is stuck or unseated, a pump with debris in it, a drive belt, a passage, a filter housing. 153 complaints end here (6%): 51 describe a stall, 15 engine damage, 14 say it came back. 115 mention the pump, 38 a belt, and 77 are Fords.

What the documents say.

• 🟢 GM 6.0L trucks and vans: "The relief valve in the oil pump is sticking or the number 1 main bearing is ... damaged." The order printed in PIP5630: the dipstick, then "Confirm oil pressure at main gallery with a manual gauge.", the filter, the pan and main bearing, and only then the pump; every revision ends "Engineering is currently working on a root cause." Its successor, 20-NA-161, names a sticking relief valve in the pump; the first version (December 2020) still asks for a manual gauge and a new filter, and the May 2021 revision drops both steps.
• 🟢 GM 2006-2018 aluminum V8s: P0521 "may be the result of a sticking oil pump pressure relief valve. In some instances, this may occur intermittently if the valve frees up when the engine cools down." (PIP4158H) On the 1.2L turbo, a pump stuck by foreign material (A202302140); on the 2020 Corvette 6.2L built to September 10, 2020, an unseated oil pressure control valve (20-NA-179); and broken piston oil jets (PIP5247A).
• 🟢 Mazda: "a piece of foreign object stuck on the oil pump pressure relief valve or oil control valve (OCV)." Measure first; the paper adds "There is no need to replace the oil filter or oil pan." (01-008/17) Mazda's 2021 bulletin for 2018-2021 CX-5 2.5L engines with cylinder deactivation blames a sticking oil solenoid valve (01-004/21).
• 🟢 Ford: a loss of oil pressure that "may be due to an engine oil pump belt tensioner" on 2018-2019 1.0L EcoSports with the 6F15 automatic, built to April 3, 2019, where "an engine replacement may be required." (SSM 49200); "This condition may be caused by an internal oil pressure leak." on the 2020-2023 Explorer and Aviator 3.0L, where, if the pump is replaced, the technician checks that the main oil gallery tube is assembled and aligned (SSM 51764).

What the owners report. Ford is 77 of the 153 (48 of them EcoSport, 25 of those mentioning the oil pump belt, the tensioner or a recall number), and BMW is next with 19. A 2012 Sierra owner: "P0521 has been addressed/replaced almost nine (9) times."

The cheap cause that gets skipped. The test before the pump. GM's first order (PIP5630) puts the dipstick, the gauge and the filter before the pan and the pump, and the May 2021 revision of its successor drops the gauge and filter steps; Mazda's puts the measurement before the pump and strainer. A pump is $400 to $3,000 in our guide; a gauge reading is $75 to $200.

Fix it yourself. Nothing on this route is a driveway job with the lamp on or a P0524 stored. Read the dipstick, find the oil change history and get a reading; a belt tensioner, a gallery tube or an oil pan is engine-opening work.

At the shop — say this: "Before an oil pump or a pan, please put a mechanical pressure reading at idle and at 2,000 rpm on the repair order, with my engine's specification next to it, and say which bulletin you are following."

Route 5 · The engine itself — owners report a median of $7,707; our guide $3,000 to $10,000+

What it is. Bearings, a crankshaft, a timing chain or a whole engine has failed, and the lamp was telling the truth. 719 complaints end here (26%): 682 (95%) describe engine damage, 419 (58%) a stall and 177 a recall or campaign. 94% mention an oil pressure warning, a low oil message or an oil light. Without the 444 Ford EcoSport complaints the share is 550 of 2,304 (24%).

What the documents say.

• 🟢 GM 6.0L: if the number one main bearing is damaged but has not spun, "replace the crank, bearings and the oil pump"; if it has spun, "replace the engine." (PIP5630C) A small GM program covers 46 vehicles of 2022 6.2L trucks and SUVs that may have main bearing cap bolts not torqued properly: "Dealers are to replace the engine." (N222360980)
• 🟢 Ford 1.0L EcoBoost, 2016-2018 Focus and 2018-2019 EcoSport with the 6F15 automatic, built to July 3, 2019: "If engine oil pressure at idle is below 10 psi and/or metal contamination is present in the engine oil, no further diagnostics should be performed." The remedy is to replace the engine (SSM 49726).
• 🟢 GM, oil cooler lines: on 2019 Silverado and Sierra 1500, "if the EOC lines detach while operating the vehicle, there will be an immediate decrease in oil pressure." (N212326940) On the 2016 CTS-V and Camaro SS a loose pickup tube can leave the bearings "starved of oil" (30990).

What the owners report. A 2018 Titan owner: "we heard a knocking noise from the engine and then the low oil warning came on. Vehicle would then not start." and they paid $17,977 for a new engine. 391 of the 719 mention an engine that was replaced or rebuilt, or that the shop said must be (most of them the second), 131 a knock or a rod, 104 a seizure and 90 metal.

The cheap cause that gets skipped. The first minute. The cheapest ending to this route is the one where the engine was switched off at the first red lamp, and the next cheapest is a tow instead of a drive. Whether the noise comes from the oil circuit is for after the tow: a tick or a knock can have other sources, but driving is not how to find out.

Fix it yourself. Nothing. The one thing in your hands is the key.

At the shop — say this: "The engine was shut off at the lamp and towed. Please read the pressure with a mechanical gauge, check the oil and filter for metal, and call me with both findings and the cost of each repair, bearings and crankshaft against a used or rebuilt engine, before anything is taken apart."

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

The status column is our computation from the printed terms, as of September 2026, not a promise from any maker. Where no end date is printed, the VIN and the warranty decide.

Campaigns, updates and emission recalls are not in the safety-recall lookup: nhtsa.gov/recalls may show nothing for them (GM's A222379711 is an emission recall), so the dealer, with your VIN, is the lookup.

What 3,010 complaints show

The set. We took NHTSA owner complaints received from January 2015 through early October 2026 that name a code or an oil pressure part (715, all sorted), a random sample of 1,500 of the 2,356 that matched only oil-warning wording such as "oil pressure light" or "low oil pressure" (the other 856 are in a published file), and 795 added by a second check of the whole file, which stopped at a limit of 800; about 1,000 more narratives of that kind were found and not sorted. Each of the 3,010 was sorted twice, independently, by the same written rules; the sorting rules and how we did it are published. The two sortings matched on 91% of them on the cause and on 97% to 98% of each yes/no question; the rest were settled by a written rule. 2,748 describe an engine oil pressure event on the owner's own car; 262 do not. The shares below describe this set, not all oil pressure complaints.

What the largest group means. "No cause or repair stated" is 39% because a complaint is often written the day the lamp comes on. It also holds cases where a part was replaced and the owner says it did not help, with no other cause named.

Who and when. Ford 703 (26%), Kia 336 (12%), Chevrolet 300 (11%), Jeep 260 (9%). The Ford EcoSport alone is 444 (16%): 206 are model year 2018 and 116 are 2019, the years of the 1.0L belt tensioner paper SSM 49200, and 122 are 2020-2021; 197 of the 444 mention the belt, the tensioner or a recall number. The median model year is 2016, and 1,401 of the 2,748 (51%) were received in 2023 to 2026.

What happened. 1,201 describe a stall (44%), 783 engine damage (28%; 719 name it as the cause), 645 a recall, bulletin or campaign (23%) and 313 a problem that came back (11%). A stall is described in 58% of the engine-damage complaints and 11% of the sensor ones; "came back" is 14% for sensors and 7% for engine damage.

Is a stall the usual ending of an oil pressure warning, and does replacing the sensor stop it? PulsCar counted what 2,748 federal owner complaints say about an oil pressure event: 1,201 describe a stall (44%), 783 engine damage (28%) and 645 mention a recall or campaign (23%), in a set built from oil pressure wording, so these are not rates. Where a complaint ends at a sensor or switch, 33 of 228 say the problem returned. NHTSA's own fields mark 10 as a crash, 43 as a fire, 11 with an injury and 322 as towed. Several bulletins print stop messages; Kia's recall 25V-099 letter says "pull over to a safe location, do not drive your vehicle". Our rule: a red lamp, a zero gauge, an engine noise or a pressure-too-low code (P0524 in any form) means stop and tow; a bare P0520 or P0521 means a pressure reading before a part.

The 56 that spell out the code. Two of them (11084828, 11118261) write only "code 520". A 57th in our set, 11694816 (2023 Tundra, engine failure), writes Toyota's extended P05202; another such Toyota, 11687704, is outside our set. 55 of the 56 describe an event on the owner's car (one, a Lincoln MKZ, does not), and 33 of those 55 state no cause.

• P0520, 22 complaints: 10705226, 10946496, 11024115, 11044781, 11084828, 11097890, 11113606, 11118261, 11128137, 11141298, 11153940, 11186976, 11281059, 11300851, 11340007, 11340916, 11342399, 11350488, 11364803, 11384610, 11400207, 11425846. All 22 are Jeep (16), Dodge (5) or Chrysler (1), model years 2012 to 2014 (17 of them 2014); 20 are the 2013-2014 years of Chrysler's 18-034-14. 16 state no cause, 4 end at a sensor and 2 at the oil circuit (a filter housing); 6 mention a bulletin about this code and 7 the warranty. 11044781: the owner says the dealer "VERIFIED THAT THE OIL PRESSURE SENSOR FAILED". 11097890: the owner writes "MY SENSOR SAYS THERE IS NO OIL PRESSURE, HOWEVER, MY CARS OIL PRESSURE IS FINE."
• P0521, 13 complaints: 10712435 (2009 Silverado: sensor replaced for about $450, same warning five months later), 11192635, 11330263 (2011 Silverado: sensors replaced, the code stayed), 11579424 (Mercedes GLC: a crankcase vent valve), 11647281 and 11725215 (Encore GX, the first naming the recall), 11652682 (2012 Sierra: replaced "almost nine" times), 11701251 (engine seized), 11730398 (scored camshaft), 11735005, 11745282 (engine blown), 11761820 and 11766711 (2019 Equinox: the sensor failed internally).
• P0522 and P0523, 8 complaints: P0522 on 11228251 and 11512983 (2012 Grand Cherokees; in one the owner's readings swing from 20 to 110 psi); P0523 on 10816662, 11363700, 11525706, 11525713, 11543670 and 11554752 (a G6, Impalas, a Ram 1500, Grand Cherokees).
• P0524, 14 complaints: 11092591 (2009 G37), 11536963 (Lincoln MKZ, not an oil pressure event), 11540358 (2015 F-150), 11609980 (2018 Titan: engine replaced), 11686430 (2024 Santa Fe Hybrid: no oil added at a service), 11709553 (2025 Sportage Hybrid), 11735199 (2019 Sorento: engine failure), 11745282 (above), 11746636 (2023 CX-5: checked, cleared, came back), 11747042 (2022 Bronco: limp mode), 11758103 (2022 Tucson Hybrid), 11762488 (2020 Telluride: engine failure), 11766660 and 11768261 (Rogue, the second a software-only visit).

What it adds up to. 8 of the 55 end at engine damage, 4 at a sensor, 4 at a pump or oil circuit, 3 at software; 33 state no cause.

When the engine dies: the safety side

Of the 1,201 complaints that describe a stall, 415 mention a highway, freeway or interstate (35%), 97 a stop sign, a light or an intersection (8%), 69 the steering (6%), 76 the brakes (6%), 288 a restart (24%) and 159 "no warning" or "without warning" (13%) (word mentions). In NHTSA's own fields, 10 of the 2,748 are marked as a crash, 43 as a fire, 11 with an injury (15 people), one with a death and 322 as towed. The death is an owner's claim, on a 2007 Escalade complaint about limp-mode shutoffs, that one person died and three were hurt; the narrative gives no detail of the crash (NHTSA's fields give December 2018, Oregon), and we cannot verify it.

The papers are blunter than the codes. 🟢 Kia's owner letter for its leaking switch: "Drive carefully to a safe location and stop your vehicle." (then: check the oil level, add oil if it is low, see a dealer; our advice is stricter: do not restart, tow) (WTY026); GM, for a pickup tube that can come loose: "the engine bearings may become starved of oil and the engine may fail" (30990). Yet the same message is sometimes false, and the makers tell their dealers so: BMW, "Engine Oil Pressure. Stop Carefully" on a new car with under 60 miles and a one-time, non-reproducible fault (SI B11 22 16). A dealer can read the fault memory and a gauge. A driver on the road cannot.

What owners say they paid

314 figures in 251 of the 2,748 complaints are ones an owner tied to a repair, test or replacement of an oil pressure event: 27 amounts paid, 44 bills, 217 quotes and 26 not stated. They are what owners wrote, not audited invoices. We publish them with NHTSA complaint numbers, and the 485 candidate figures left out (vehicle prices, tow costs, other repairs) are listed with the reason. The medians by group are in the price ladder above; the gauge (4 figures) and wiring (3) groups are too small to trust. For bills and amounts paid only: engine 25 figures, median $7,000 ($970 to $19,000); sensor or switch 12, median $497 ($40 to $3,000).

Why the code or the lamp comes back

The part was not the cause. 33 of the 228 sensor complaints say the sensor or switch failed again or the problem returned; a Grand Cherokee owner (not in that count) replaced the sensor three times, the third time with the filter housing and the oil pump, and P0520 returned within about a week. The cause is intermittent. 🟢 GM: a sticking relief valve "may occur intermittently if the valve frees up when the engine cools down" (PIP4158H). The fix is software that cannot clear it. 🟢 Mazda: P0524 on 2019 CX-3, Mazda3 and MX-5 and 2018 Mazda6 in California "cannot be cleared even after the concern that created the DTC has been resolved" until the computer is reflashed (SSP C0). The maker took years to name the cause. 🟢 GM's 6.0L paper PIP5630 and its revisions A to D (2019-2020) say "Engineering is currently working on a root cause." in every revision; the 2020-2021 successor, 20-NA-161, points to a sticking relief valve in the pump. The fix came later. 🟢 Audi's first RS 3 paper says a solution is "forthcoming in the 2nd quarter of 2023" and its successor prescribes the software.

Can you drive with P0521 or P0520?

It depends on what else you see, and this is our advice, not a maker's rule. A red oil pressure lamp, a gauge at zero, ticking, knocking or rattling from the engine, or a code that says the pressure itself is too low (P0524 in any form, such as Mercedes' P052497 or Toyota's P052477): pull over safely, switch the engine off and have it towed. Do not drive it to a shop, do not restart it to listen, and do not top up and carry on; no distance is safe, because a real loss of pressure can starve the bearings and fail the engine. Carmakers' service papers print the stop in their own words: Porsche 911 GT3, "Stop the engine immediately."; MINI, "Engine oil pressure. Stop carefully"; GM, on detached oil cooler lines, "Oil Pressure Low Turn Vehicle Off" and "a loss of propulsion is possible". No bulletin in our set tells an owner to tow, but Kia's recall 25V-099 letter for the 2021-2023 Soul and Seltos with the 2.0L engine does, for engine noise, the oil pressure warning light or a loss of drive power: "pull over to a safe location, do not drive your vehicle" (more in our low oil pressure guide). For every other car the tow is our advice, and it is cheaper than the engine on the price ladder.

A bare P0520 or P0521, with no red lamp, no noise, a normal gauge (if the car has one) and a correct oil level: a shop within days, not weeks, with a pressure reading asked for before any part; drive gently and stop at once at a red lamp or any noise. The papers that call a code false (BMW, Mercedes, Porsche, Audi) say so to dealers who can measure the pressure. If the amber light turns red, or a noise starts, you are in the first case. P0524 in any form, with no lamp and no noise: the code reports the pressure itself, so treat it like the red lamp: get safely stopped, switch off and have the car towed (check the level on level ground once the engine is cool, and ask for the pressure reading at the shop); do not drive on.

A flashing check engine light: pull over safely, switch the engine off and have it towed; the only exception is a shop within 2 to 3 miles, reached gently, under 40 mph with light throttle (our advice). That exception does not apply with a red oil lamp, a gauge at zero, P0524 in any form or any engine noise: for those, switch off and tow. If the engine stalls on the road, hazard lights, steer to a safe place with the momentum you have, and expect heavier steering and brakes. See also stalling while driving and flashing check engine light.

Should you buy a used car with a P0521 or P0520 history?

Ask what was found, not what was replaced. 10 of the 45 complaints that end at checked-and-cleared say the problem came back, and so do 33 of the 228 sensor complaints. Ask for the invoice that names the test (a pressure reading, the bulletin followed), have a dealer run the VIN for the recalls above, and check that the oil on the stick is clean and at the mark. A car whose engine was replaced after an oil pressure warning is a different purchase from one with a replaced sensor. The used-car inspection checklist covers the rest.

Clearing P0521 or P0520 before an inspection

A cleared code returns if the cause is still there, and stations want the car's emissions self-checks to have run again after a clear; ask how many trips. Do not clear a code to pass: the pressure may be really low. The papers show why codes sometimes will not clear: GM's recall A222379711 exists because the computer "may not clear the permanent status" of P0521, and Mazda's SSP C0 says a P0524 stays stored after the cause is gone, in cars that must pass California's Smog Check. Fix first, drive several normal trips, then test; how to reset a check engine light covers the mechanics.

What the papers tell a shop to do with an oil pressure code, checkpoint by checkpoint

1 The lamp and the noise: stop. 2 The level and the oil change history. 3 Every code, with the freeze frame. 4 The connector and the harness. 5 The VIN. 6 A mechanical pressure reading on the repair order. 7 Only then a part, in the order the paper for your engine prints.

Three oil pressure code traps

Trap 1 · Buying a sensor from the code. Of the 46 families of passenger-vehicle papers that print P0520 to P0524, only 3 end at a sensor or switch, and 33 of the 228 sensor complaints say it failed again or the problem returned. Ford's SSM 47072 says "If unable to determine root cause, do not attempt any repairs."

Trap 2 · Driving on with a lit lamp, or trusting a dark one. The Santa Fe owner drove 3 to 5 miles with no oil and no lamp; the Telluride engine failed with no oil warning at all. The lamp may not warn in time: the dipstick and the stop come first.

Trap 3 · A cleared code or "checked, found nothing" taken as a repair. 45 complaints end that way and 10 say the problem came back. Ask for the freeze frame and the pressure reading on the repair order, not a clear.

The oil pressure code plan: 10 minutes, today, this week

If the red lamp is lit, the gauge reads zero, the engine is noisy or the code is P0524 in any form, stop, switch off, tow, now. Today (10 minutes). Read the dipstick, look at the connector and harness, write down when the code or lamp appears and what changed first, and read all the codes with the freeze frame. Today (VIN). Ask a dealer for recalls, campaigns and updates. This week. If a bare P0520 or P0521 persists, pay for one diagnosis and ask for a mechanical pressure reading, the bulletin followed and the software level. A flashing check engine light means a tow, or a shop within 2 to 3 miles, gently, under 40 mph, but never with a red oil lamp, a gauge at zero, P0524 in any form or any engine noise. All of those mean now, not this week.

These are composite scenarios, not individual customers; the dollar figures are shop-price ranges from our guides. A 2014 Jeep shows an amber light and P0520, the engine is quiet and the oil is at the mark: the owner asks for a mechanical pressure reading and for the VIN to be run against bulletin 18-034-14 before agreeing to a sensor at $90 to $450 installed. A truck's red oil lamp comes on at 45 mph: the driver pulls over, switches off and has it towed, then asks for the pressure reading at $75 to $200 before anyone sells an oil pump at $400 to $3,000. A hatchback shows P0521 days after an oil change: the owner asks which filter was fitted and for the level to be checked before a sensor or a pump.

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: PIP5272A, PIP4158H, PI0699B, PIP5198A, PIP4690G, PIP5121C, PIP5630, PIP5630A, PIP5630B, PIP5630C, PIP5630D, A202302140, 20-NA-161, 20-NA-179, PIP5247A, PIP5750A, PIP5826B, 18-NA-246, A222379710, A222379711, PIP5844, PIP6125, 16118, 14159A, 30990, N212326940, N222360980, 18-NA-114.
2. Ford: SSM 46253, SSM 46526, SSM 47072, SSM 49200, SSM 49726, SSM 50988, SSM 51764.
3. Chrysler, Jeep, Dodge, Ram (Stellantis): 18-034-14, 18-108-15, 18-082-16, 18-103-16 Rev. B, 18-013-13, S2109000001, S2108000168, 09-006-23, 08-086-25.
4. Mazda: 01-008/17, 01-014/15, 01-020/18, SA-055/20, SA-048-26, SSP C0, 01-004/21.
5. Toyota, Lexus, Subaru, Nissan, Kia, Honda: Toyota T-SB-0104-21 Rev. 2; Lexus LSC 9LH extension; Toyota LSC extension letter; Subaru 02-141-13R, 02-162-15; Nissan PC551; Kia WTY026 dealer letter, WTY026 owner letter, ENG237, ENG237 Rev. 2, PS719; Honda ATS 170801.
6. Audi, Porsche, BMW, MINI, Mercedes-Benz, Bentley, others: Audi 2041093/3, 2068121/1, 2067756/2; Porsche 76/16, 2010.3; BMW SI B11 22 16, SIB 11 03 24; MINI SI M11 06 15; Mercedes-Benz LI18.00-P-058770, LI18.00-P-073137; Bentley 2081029/1; Rolls-Royce A 02 2021 03; McLaren KA-01620; Land Rover N805.

Data and method: complaints, amounts, excluded figures, documents, complaints not sorted, the sorting rules and how we did it (CC BY 4.0).

What this page cannot tell you

The complaint file holds cases where an owner wrote to NHTSA, in the owner's words, with no check; owners whose trouble ended are mostly not in it, and a complaint is not a failure rate. The 3,010 are the oil pressure complaints we sorted, not all of them: 856 more that matched only warning wording were left unsorted, and about 1,000 further narratives of that kind were found and not sorted. Only 56 spell out P0520 to P0524 (plus two Toyota extended forms). Many complaints do not say whether the pressure was measured, so a lamp in a narrative is not proof that the pressure was low. A paper NHTSA's index does not list is not here, heavy-truck papers were not sought, and a bulletin tells you what a maker told its dealers, not what is wrong with your car. Coverage statuses are our arithmetic from printed terms. For P0520 and P0521 the evidence is the lamp, the noise, the oil level, the freeze frame and a mechanical pressure reading; a code read alone is not a diagnosis.

Neighbouring pages: low oil pressure warning, oil change cost, oil leaks, oil leak repair cost, P0172, engine knocking, ticking noise, blue smoke, stalling while driving and the check engine light.

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.

Did the lamp turn out to be a sensor, a filter, a recall or the pump? Email [email protected] with the vehicle, mileage and outcome.