The Lemon IndexThe two gas pedal position signals disagree, so the car may go into reduced power or not respond to the pedal. Full P2138 page
77 owner complaints · the #1 code Subaru Outback owners name · 68% of Subaru Outback complaints that name a code (every car: 1.7%)
Middle of 116,000 miles · most between 94,000 and 152,000 (72 owners gave it)
Subaru Outback owners named P2138 in 77 complaints to the U.S. government (NHTSA), most often on the 2006, 2005 and 2007 model years, at a middle of 116,000 miles. The part they name most is the throttle body (7 complaints). Complaints are owner reports, not proof of a defect.
Subaru Outback model years that report P2138
Owner complaints naming P2138, by model year. Raw counts: years that sold more get more complaints, so this is each model year's record, not a failure rate.
Mileage when it happened
116,000 miles is the middle of what 72 owners entered. Half were between 94,000 and 152,000 miles.
The mileage on the complaint form, when the owner gave one.
What owners say caused it or fixed it
The most-named part is the throttle body, in 7 of the 77 complaints (9%). 2 of those mention it being replaced or repaired, and 2 say the problem came back afterwards.
- Throttle body7 complaints2 mention a repair or replacement, 2 of them say the problem came back · what owners paid
15 complaints mention a recall.
Counted from the owners' own words: a part counts when a sentence names it with a cause or repair word. What owners wrote, not a diagnosis. A shop should confirm the cause before replacing parts.
Symptoms owners describe with P2138
69% of these complaints say the check engine light came on.
- Loses power or goes into limp mode26%20 of 77 complaints
- Stalls or shuts off10%8 of 77 complaints
- Flashing check engine light10%8 of 77 complaints
- Warning lights and electrical faults5%4 of 77 complaints
- Brakes or ABS act up3%2 of 77 complaints
Share of the complaints naming P2138 whose text also describes each problem. A complaint can describe more than one.
Keep going
- P2138: meaning, causes and every car that reports it
- Subaru Outback reliability by year
- 2006 Subaru Outback problems and recalls
P2138 on other cars
Chevrolet Malibu (51) · Chevrolet Impala (18) · Subaru Legacy (18)
The details
How we count
We read every owner complaint in the NHTSA file whose text names this trouble code, and count the ones filed about this model (matched by the make, model and model year on the complaint). Mileage is what the owner entered on the form.
Parts: a complaint counts for a part when one of the owner's own sentences names that part together with a cause word (failed, bad, diagnosed, caused by, leaking ...) or a repair word (replaced, repaired, new, reprogrammed ...). "Came back" means the same complaint also says the problem returned or the repair didn't fix it. These are counts of what owners wrote, not a diagnosis, and one complaint can name several parts.
Complaints are reports, not proof of a defect, and most owners never file one. Popular models get more complaints, so the counts are not a failure rate. The code meaning is the standard SAE J2012 definition in our own words, or the carmaker's meaning where we verified it for that make.
What P2138 means
The two gas pedal position signals disagree, so the car may go into reduced power or not respond to the pedal.
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
- Failing accelerator pedal sensor
- Wiring or connector fault
- Throttle body fault
Check the complaints yourself
NHTSA complaint numbers (search them at nhtsa.gov): 11724365, 11445826, 11436850, 11398751, 11396931, 11378582, 11376455, 11373843, 11307590, 11306563, 11300105, 11299992 and 65 more.
Quick answers
What does P2138 mean on a Subaru Outback?
Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation. The two gas pedal position signals disagree, so the car may go into reduced power or not respond to the pedal.
Which Subaru Outback years have the most P2138 complaints?
In complaints to NHTSA, owners of the 2006 (59), 2005 (13), 2007 (5) Subaru Outback named P2138 most (77 complaints in all, 2005–2007). Raw counts, not a failure rate.
What fixes P2138 on a Subaru Outback?
Owners most often name the throttle body (7 of 77 complaints). That's what owners wrote, not a diagnosis: have a shop confirm the cause with a scan and tests before replacing parts.
At what mileage does P2138 show up on a Subaru Outback?
Owners who gave their mileage reported a middle of 116,000 miles; half were between 94,000 and 152,000 (72 owners).
Can I drive my Subaru Outback with P2138?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
Sources: NHTSA owner complaints that name P2138 on the Subaru Outback, counted by The Lemon Index; NHTSA recalls; repair bills owners named. Meanings: SAE J2012 in our own words. Owner reports, not a diagnosis or repair advice for your car.