P0AC4 · Manufacturer communications

CADILLAC · 2020-05-06

This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and "Reduced Propulsion" messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global Diagnostic System 2 is up to date. Technician will need to use Global Diagnostic System 2 and check all modules for Diagnostic Trouble Codes. Now use Global Diagnostic System 2 to create freeze frame data from Hybrid Powertrain Control Module and the Engine Control Module and save a report. Technician will need to verify that the vehicle had not been run very low or out of fuel. Also verify the…

CADILLAC · 2019-04-15

This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and ?Reduced Propulsion? messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global Diagnostic System 2 is up to date. Technician will need to use Global Diagnostic System 2 and check all modules for Diagnostic Trouble Codes. Now use Global Diagnostic System 2 to create freeze frame data from Hybrid Powertrain Control Module and the Engine Control Module and save a report. Technician will need to verify that the vehicle had not been run very low or out of fuel. Also verify the…

CHEVROLET · 2018-01-18

This Bulletin provides ECM reprogramming information to Correct DTC P3260 and P0AC4.

CHEVROLET · 2017-07-26

This Preliminary information communicates to dealers on how to diagnose and repair the vehicle if it setsDiagnostic trouble codes P0AC4 (ECM) and P2797 (HPCM)

CHEVROLET · 2016-07-15

27660 - Service Update. The engine may stall, followed by a Driver Information Center (DIC) message ?Action Required-Engine Not Available?. This will also cause diagnostic trouble codes P0AB9 (Hybrid/EV System Performance) and P0AC4 (Hybrid/EV Powertrain Control Module Requested MIL Illumination) to set. The engine will not start until the key is cycled. Dealers will reprogram the drive motor power inverter module.

CADILLAC, CHEVROLET · 2014-12-08

This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and ?Reduced Propulsion? messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global Diagnostic System 2 is up to date. Technician will need to use Global Diagnostic System 2 and check all modules for Diagnostic Trouble Codes. Now use Global Diagnostic System 2 to create freeze frame data from Hybrid Powertrain Control Module and the Engine Control Module and save a report. Technician will need to verify that the vehicle had not been run very low or out of fuel. Also verify the…

CADILLAC, CHEVROLET · 2014-05-21

This Preliminary Information communication provides information to the technician the steps to diagnose and repair vehicles that have Check Engine Light illuminated with an "Engine Unavailable" and "Reduced Propulsion" messages on the Driver Information Center. Technician may find Diagnostic Trouble Codes a P0AB9 and P0AC4. Technician should not clear any Diagnostic Trouble Codes and ensure Global Diagnostic System 2 is up to date. Technician will need to use Global Diagnostic System 2 and check all modules for Diagnostic Trouble Codes. Now use Global Diagnostic System 2 to create freeze frame data from Hybrid Powertrain Control Module and the Engine Control Module and save a report. Technician will need to verify that the vehicle had not been run very low or out of fuel. Also verify the…

CADILLAC · 2014-05-07

This Preliminary Information communication provides information to the technician about vehicle that may have the following Diagnostic Trouble Codes U0401, U0140, P15F6, P1E00, U0100, P0562, P1553, P0AC4, C0110, C0898, P1EFC, P257F, P150D, P150E, C0899, U1860, U0293, C0196, P069E, U2608, U0101, U186B, P1ADE, P1AE0, P1E19, U0073, P1EDD, U0417, U184D, U1858, and C12E0 set as Passed /Failed. Technician will need to contact General Motors Technical Assistance Center for further assistance.

CADILLAC, CHEVROLET · 2014-01-08

This Preliminary Information communication provides information to the technician about vehicles that have a Check Engine Malfunction Indicator Lamp on and possibly an Engine Unavailable message on the Driver Information Center. Technician may find Diagnostic Trouble Code?s P0AB9 in set in the Hybrid Powertrain Control Module and P0AC4 set in the Engine Control Module. Technician should not clear any Diagnostic Trouble Codes. Technician will need to verify that the vehicle has not been run very low or out of fuel, customer did not key off while driving, and the engine runs properly and no other engine related or communication related Diagnostic Trouble Codes are present. Technician will need to check for clean and tight ground location G106 and G113.