Fault Code Lookup › Powertrain codes › P0138
P0138 Powertrain · generic OBD-II
O2 Sensor Circuit High Voltage
P0138 is a standard code covering engine, transmission, fuel and emissions. It names the system that logged the fault, not the part that failed. Below: which cars owners reported it on, what happened, and recalls on those cars, from 4 complaints filed with NHTSA. Updated November 9, 2026.
- 4owner reports
- 2car models
- 0mention a crash
- 0mention a fire
- 2012–2017model years
Which cars get code P0138?
Every model whose owners mentioned P0138 in a complaint, most reports first. Each year opens that car's full problem report. Popular models collect more reports because more of them are on the road.
Chevrolet Equinox
1 reportWhere does P0138 show up?
By brand
- Chevrolet4
Component the owner filed it under
Is there a recall for P0138?
As of November 9, 2026, no NHTSA recall on the cars reporting P0138 names this code or its most-reported component. Recalls can be issued at any time: check your VIN at nhtsa.gov/recalls.
What happened when owners saw P0138?
4 of the 4 reports, spread across the models above, as the owners wrote them. NHTSA removes names and VINs; long reports are trimmed. CarHooq has not verified individual claims.
OBD2 codes ran on vehicle show: P0138 ("O2 sensor circuit High voltage bank 1 sensor 2") P013E (unknown) P2138 ("Throttle/Pedal Position Sensor Switch D/E Voltage Correlation") Vehicle is getting poor fuel mileage and has a drastic delay in acceleration after pressing the gas pedal, putting driver in immediate danger in traffic.
…The engine lite continues to come on intermittently and the scans continue to indicate a problem with the O2 sensor: code on [XXX] =P0138 code on [XXX] =P2271 I returned to Lou bachrodt on may 3,25 while the lite was on. As I drove into the service area the service greeter advised me to drive up and wait for the service advisor-Charles. I proceeded to turn off he vehicle and wait. As soon as I turn the vehicle back on to show Charles the engine lite, it was no longer on. And once again I was told that if the lite was not on he could not run the scan or accept the scan report from Auto Zone from the day before. He also seems to be fixated on the transmission code that no longer comes up in…
I PURCHASED A 2017 CHEVY MALIBU IN APRIL 2017 WITH 11 MILES. IN LESS THAN A MONTH, THE CAR STARTED HAVING ISSUES. TOOK THE VEHICLE INTO THE DEALERSHIP FOR INSPECTION WITH THE INITIAL PROBLEM BEING THE O2 SENSOR THEY UPDATED THE SOFTWARE AND IT WAS NOTED GM WOULD MONITOR THE CONCERN AND HAS BEEN AN ONGOING ISSUE SINCE. THE PROBLEMS ARE AS FOLLOWS: DASHBOARD GOES BLANK WHILE DRIVING, CODES: P0036, P0037, P0138, P0141, P2097 X3; P2122, P2127, P2138, ACCELERATOR PEDAL REPLACED X3 WITHIN A TWO MONTH TIME FRAME WITH THROTTLE HARNESS BEING REPLACED ON THE THIRD TIME, REDUCED ENGINE POWER TO 20 MPH WHILE DRIVING, SCANNING NOISE COMING FROM ENGINE WHILE VEHICLE IS BOTH IN THE ON/OFF POSITION; STILL…
The contact owns a 2017 Chevrolet Malibu. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to an independent mechanic to be diagnosed. The mechanic retrieved fault code: P0138 (engine control module (ECM). The vehicle had unknown repairs completed; however, the failure recurred. The contact made the independent mechanic aware of the failure; however, the vehicle was not taken back to be diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was unknown.
P0138: questions drivers ask
What does code P0138 mean?
P0138 is a generic OBD-II powertrain code. Its standard definition is "O2 Sensor Circuit High Voltage". The code tells you which system set the fault, not which part failed; the owner reports on this page show what it meant in practice for 2 car models.
Which cars get code P0138 most often?
In NHTSA owner complaints, P0138 is mentioned most for the Chevrolet Malibu (3), Chevrolet Equinox (1), across 2 models and model years 2012 to 2017. Popular models collect more reports because more of them are on the road.
Is there a recall for code P0138?
As of November 2026, no NHTSA recall on the cars reporting P0138 names this code or its most-reported component. Recalls can be issued at any time, so check your VIN at nhtsa.gov/recalls.
What should I do if my car shows P0138?
Write down when the code appeared and what the car did (warning lights, loss of power, noises, speed, weather). Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer or independent workshop to read the stored freeze-frame data before anyone clears the code, and keep the repair order. If the car loses power in traffic, stop driving it. CarHooq does not diagnose: these are owner reports and official recall notices, not repair advice.
How this page was made
CarHooq read the text of every owner complaint filed with NHTSA for 19 US and European brands (model years 2012 onwards) and picked out the diagnostic trouble codes owners wrote down. This page lists every mention of P0138. The definition is the generic SAE J2012 wording; a carmaker may use the code slightly differently. Nothing here is a diagnosis. More answers: the fault code FAQ. Data: NHTSA Office of Defects Investigation (public domain), retrieved November 9, 2026. How CarHooq reports are made.
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