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CUSTOMER CONCERN Customer states the traction-control warning light comes on intermittently. EBCM DTC C0561-71 is stored. CAUSE Traction-control switch input testing on the Brown/White circuit 1571 isolated an intermittent terminal connection at the traction-control switch connector. CORRECTION Clean and repair traction-control switch connector terminals, clear DTC C0561-71 and verify the BCM switch input remains in the enabled state.

CUSTOMER CONCERN Customer states the engine oil-pressure gauge intermittently drops to 0 psi without abnormal engine noise. DTC P0521 is stored. CAUSE Mechanical oil-pressure testing remained normal while the scan-tool and dash readings dropped, confirming a failed engine oil-pressure sensor. CORRECTION Remove and replace engine oil-pressure sensor and inspect or replace the sender screen beneath it. Clear DTC P0521 and verify stable oil-pressure readings.

CUSTOMER CONCERN Customer states the engine will not crank after a front-end collision. No relevant DTC is initially stored. CAUSE Serial Data Gateway Module data showed Crash Detected, confirming the high-voltage impact-detection system had disabled propulsion. CORRECTION Inspect and repair high-voltage impact sensor circuit as required, perform HPCM 300-volt impact-status reset and secured high-voltage DTC reset, then verify normal cranking.

CUSTOMER CONCERN Customer states the engine misfires on cylinder 1. DTCs P0300 and P0301 are stored, and running compression measures approximately 13 psi. CAUSE Cylinder-deactivation testing confirmed the valve lifter oil manifold was not maintaining Active Fuel Management lifter operation. CORRECTION Remove and replace valve lifter oil manifold. Inspect AFM lifter and valve spring condition, clear DTCs P0300 and P0301 and verify cylinder contribution.

CUSTOMER CONCERN Customer states the engine intermittently stalls during an automatic restart and usually will not restart. The Service Hybrid System message is displayed. CAUSE Testing under GM bulletin PIT4808 confirmed an internal failure in the hybrid battery pack. CORRECTION Remove and replace hybrid battery pack. Perform sequential EBCM, HCP, ECM, TCM and BECM programming with current calibrations and verify automatic start operation.

CUSTOMER CONCERN Customer states the vehicle will not crank. DTCs P0AC4, U1888, U1875 and U1878 are stored. CAUSE DLC resistance, fuse-feed and expansion-bus testing isolated an open or high-resistance circuit in the drive-motor generator power-inverter module wiring. CORRECTION Repair drive-motor generator power-inverter module wiring and connector terminals. Clear network and hybrid DTCs and verify module communication and normal cranking.

CUSTOMER CONCERN Customer states the security indicator does not illuminate with the key removed. DTCs B2287 and B2289 are stored. CAUSE LIN communication measured 5.9 volts at rest and a 12-volt pulse with the power button pressed, but the ID code box did not supply the required 5-volt reference. Inspection found broken wiring at the J25 junction connector in the right kick-panel area. CORRECTION Repair broken ID code box wiring at J25 junction connector and restore terminal

CUSTOMER CONCERN Customer states there is no heat inside the vehicle. DTCs P1116, P1121 and P1122 are stored. CAUSE Active testing showed the coolant heat-storage water-valve position signal did not follow commanded positions, confirming a failed coolant flow-control valve. CORRECTION Remove and replace coolant flow-control valve. Refill and bleed engine cooling system, clear DTCs and verify cabin heat operation.

CUSTOMER CONCERN Customer states the vehicle will not start after collision repair. DTC P0A0D is stored. CAUSE Inspection confirmed the high-voltage battery service plug was not fully installed, leaving the interlock circuit open. CORRECTION Correctly install and lock high-voltage battery service plug. Clear DTC P0A0D and verify READY-mode operation.

CUSTOMER CONCERN Customer states the check-engine and master warning lights are on. DTCs P0A80 and P3193 are stored, although the engine appears to run normally. CAUSE Hybrid-battery block-voltage testing confirmed abnormal voltage variation inside the high-voltage battery pack. CORRECTION Remove and replace high-voltage battery pack. Clear hybrid-system DTCs and verify battery block voltages remain balanced.