P0AC4 fault code: what 9 Chevrolet owners reported

…Below is a list of all the CEL codes that were pulled: P06DB P0030 P0031 P0403 P0405 P0443 P0458 P0489 P0597 P0598 P06DA P0AC4 P0135 P0AC4 P16E0 Looking into this issue I found that this is an one of the most common failures in the Chevy Volts but is no longer covered under the vehicle warranty and no bulletins posted for an extended warranty other than the BECM failure. This failure is so prevalent that I am surprised it is not.

two recalls in the past year is suppose to address the battery fire safety issue announed by gm in late 2020. days after the final software fix by gm weeks ago, the "check engine" light was lit on my chevy bolt. a follow up service appointment was needed to replace faulty hardware. today, after gm announced a THIRD recall. I used a popular third party obd2 app to check the health of my chevy bolt, 4 different issues were reported: U0293, P0AC4, U0100, and U0073. Note that GM software reports zero issues from GM's app. At this point, I trust what the third party app is reporting and NOT GM's app. It appears GM is hiding these issues from Chevy Bolt owners. I have a service appointment with…

Vehicle periodically throws P0964 and P0AC4 related to TSB PIC6330. Recently, this has led to poor running of internal combustion engine and low/undrivable power, almost leaving me stranded. Took multiple restarts before I could drive the vehicle. The TSB indicates to replace part# 24285319 (internal transmission solenoid control harness) however GM indicates they have discontinued manufacture of this part. How am I supposed to get my 6 year old car fixed if GM doesn't supply the part?

Vehicle is 2018 Chevrolet volt with approx 91000 miles, purchased new in California with both PZEV and Voltec warranties in place. Vehicle produced MIL in December, in Colorado, with exterior temperatures ~30 degrees, after attempting to remote start. The resulting OnStar Codes P1AEE, P1AEF, and P0AC4 indicating "the electric propulsion system is not performing as expected. Please service immediately." Drove the vehicle to the nearest dealership assuming there could be an unexpected loss of power. Identified PIC6285B as trouble shooting aid for the dealership. The dealership stated they contacted their GM TAC representative and the service foreman and TAC agreed the vehicle needed a…

Vehicle lost propulsion and all power mid turn at approximately 45mph. Powe steering and assisted brakes were gone. Conditions were rainy, resulting in single car crash. Car did not restart. No codes present. Occurred again after repairs at 70mph on highway. Codes P0AC4 and P0C0E indicating Drive Motor Power Inverter B. Despite being under warranty, GM cannot repair, and has no replacement parts. GM has ignored messages requesting buyback per federal law.

…P0AC4, 3. P1E00, 4. P1B0B, 5. P1B43, 6. P1E1E, 7. P0AC4, 8. P1E00, 9. P0A46, 10. P1AF0, 11. P1AF2, 12. P1B0B, 13. P1B43, 14. P1E1E, 15. P1E22, 16. P0A46, 17. P1B0B, 18. P1B43, 19. P1E1E. Per the OBD2 code reader, the primary code was P0A46 (Drive Motor 2 Position Sensor Performance). As of 1/9/23, the dealer has indicated that the primary problem is with the entire Transmission assembly which requires replacement. The replacement assembly is not in stock, is back-ordered and there is no ETA to receive the transmission assembly. The vehicle has 32243 miles on it.

…(It slowed my car down significantly while on highway and eventually stop with message on the console says engine offline) With the following error codes found: P0031 P0054 P0030 P0135 P0403 P0405 P0443 P0458 P0489 P0597 P0598 P06DA P06DB P0AC4 P0030 This car barely has much gas mileages as it was primarily on electric, but this failure on highway comes suddenly.

I WAS DRIVING ON FREEWAY AT 65 MPH THEN ALL THE SUDDEN I GOT CHECK ENGINE LIGHT ONE AND MESSAGE "ACTION REQUIRED, SHIFT TO PARK", I NOTICED THE DOOR UNLOCKED BY ITSELF AND THE CAR STARTING TO LOSE PROPULSION, I GLIDED OFF THE FREEWAY AND STOPPED AT THE END OF OFF RAMP DUE TO RED TRAFFIC LIGHT, THEN THE CAR CAN NOT START AGAIN. AFTER TOW TRUCK CAME, THE CAR STARTED AGAIN AND I WAS ABLE TO DRIVE TO DEALER FOR REPAIR. DEALER FOUND TWO ERROR CODES IN THE HISTORY P0AC4 AND P0604. ALTHOUGH THE CAR IS WORKING FINE AT THIS MOMENT AND SEEMS LIKE IT WAS JUST SOME SORT OF COMPUTER CRASH, HOWEVER IT WAS VERY DANGEROUS TO LOSE PROPULSION ON THE FREEWAY AND STUCK ON A HEAVY TRAFFIC OFF RAMP.

…MANAGE TO START INTERNAL COMBUSTION ENGINE THIS TIME, AND CRIPPLE CAR 7 MILES INTO DEALERSHIP,WHERE MECHANIC PULLS DTC'S P0AC4,P1E00,C12FE AND UPDATES VEHICLE SOFTWARE WITH GM TSB PIC5803C-"CHARGE INCOMPLETE-CHARGE INTERRUPTED AND MIL WITH DTCS P0D3E OR P0D3F WITH P1E00" FIXING PROBLEM.MY MAIN COMPLAINT WITH GM ON THIS ISSUE IS THAT THIS SOFTWARE UPDATE WAS RELEASED 6/7/2013 AND I HAD JUST HAD THIS VEHICLE IN DEALERSHIP FOR ANOTHER SOFTWARE UPDATE 3 MONTHS AGO-12/2/13.WHY DIDN'T GM PROVIDE THE PIC5803C UPDATE AT THE SAME TIME AS THAT ONE, AVOIDING A DANGEROUS ENGINE FAILURE THAT OCCURRED IN TRAFFIC AT HIGHWAY SPEEDS?CONTACT WITH GM ONLY REVEALS THAT SOFTWARE PATCHES ARE APPLIED IF A FAILURE…