PULSCAR ANALYSIS - P0103 AND P0102 (MASS AIR FLOW SENSOR CIRCUIT HIGH / LOW INPUT) IN NHTSA'S PUBLIC FILES PulsCar analysis of NHTSA public data, October 2026. License: CC BY 4.0 Attribution: "PulsCar analysis of NHTSA public data, October 2026." Published alongside https://www.pulscar.io/blog/p0103-code ------------------------------------------------------------------------------ Prepared October 2026. Source data: NHTSA public flat files (complaints received 1 January 2015 to 4 October 2026 - the latest received date in the files; the latest complaint in this set was received 1 October 2026; manufacturer communications; recalls since 2010; investigations) and documents downloaded one at a time from static.nhtsa.gov. 1. Complaints (664) First search (575): every complaint whose narrative names P0100, P0102, P0103 or P0104 by any spelling we searched (a letter O for zero, a space, hyphen or period after the P, the suffix 00, or a bare 100, 102, 103 or 104 after "code", "DTC", "error", "CEL", "coded" or "fault"), or names the mass air flow sensor in owners' words (mass air flow, MAF, air flow sensor or meter, air mass meter, volume air flow) together with a word about a fault, a repair or a symptom. Second search (89): an independent search of the same file for what the first one missed, run after the first batch was sorted; every complaint it proposed that meets the unchanged relevance rule was added. found_by in the complaints file says which search found each complaint. Sorting: the sorting rules (codebook.txt) were written, dated and fingerprinted before any complaint was sorted; an addendum for the second batch was fingerprinted before that batch was sorted. Every complaint was sorted twice, independently, by the same written rules, each time from the rules alone, without sight of the other sorting. One category (N not a mass air flow fault on this vehicle; S sensor named or replaced; D sensor cleaned or dirt named; W wire, plug or connector; A air filter, duct, boot or leak; F software or a campaign procedure only; O another cause; K checked and cleared; U no diagnosis or repair stated) and four flags (stall, nostart, recall, returned). Where the complaint gave the sorter only an excerpt around the matching words, the complete text was used when the excerpt did not decide the question. Agreement over all 664: category 537 (80.9%); stall 629 (94.7%); nostart 659 (99.2%); recall 652 (98.2%); returned 632 (95.2%). Settling: every disagreement was read and settled by one of the written rules R1 to R8 (listed in codebook.txt); the rule applied is in the rule_applied column. A consistency check then changed 32 agreed rows under the same rules (resolution says "changed in consistency pass"). Result: 579 relevant, 85 not relevant. Counts are counts of complaints, not cars. A complaint is evidence that an owner wrote to NHTSA; nothing here is a failure rate. 2. Documents (351 files, 283 distinct documents) First search: NHTSA's index of manufacturer communications, entries whose summary names P0100, P0102, P0103 or P0104, or names the mass air flow sensor with a word about a fault, a repair or a software update; hands-free module, radio and Bluetooth bulletins set aside: 258 documents. Second search: 94 more documents found by the independent search. One document had no PDF on NHTSA (10107195). Reading: 137 representative documents were read in full; 147 further files (revisions, copies and look-alikes of those) were compared with the representative line by line; 67 files (flash bulletins that list the sensor only among dozens of codes, and heavy-truck papers) were checked for the four codes and the sensor's name in their own text and were not read through. A few papers whose text did not read cleanly (3 with no readable text, some with scrambled tables) were read from images of their pages. Every verbatim quotation in the article was checked against the text of the named document. The document list says, for each file, what was done (column read), which codes its own text names, and its relevance (DIRECT: about the target fault; LISTED: a target code is one of many in a list; RELATED: a companion code or the sensor in the same family; NOT RELEVANT). Model years, engines, build dates and coverage terms are as printed in the documents, never taken from NHTSA's index, which expands years. Coverage status "as of September 2026" is the authors' computation from printed terms. duplicate_of marks exact copies (same text as another file); 68 of the 351 files are exact copies, leaving 283 distinct documents. 3. Owner-reported amounts (44 figures in 40 complaints) One written inclusion rule (amounts below, fixed before the figures were decided): a dollar figure is included when the owner states it as a price, charge, bill or quote for diagnosing, repairing, cleaning or replacing the mass air flow sensor, its connector or wiring, the air filter or intake duct on its air path, or a diagnostic fee for that event, on that vehicle. Excluded: mileage written as "NNk"; vehicle values, payments, trade-ins; other systems; totals that mix the sensor with other work unless the owner attributes the figure to the sensor; restatements; other owners' costs. Status comes from the owner's own words (paid, billed, quoted, offered, not stated). 70 figures were excluded; each exclusion and its reason is in the notes of the analysis. Figures are what owners wrote, not audited invoices. 4. Limits The complaint file holds the cases where an owner wrote to NHTSA, in the owner's words, with no verification; owners whose trouble ended are mostly not in it. The shares reported (for example how many sensor replacements were followed by a return of the problem) describe the complaints, not all cars. The document set holds what NHTSA's index lists; a maker paper that is not in the index is not in it.