CUSTOMER CONCERN Customer states the ABS, brake and traction-control warning lights are on. DTCs C1241, C1256 and C1391 are stored. CAUSE Accumulator-pressure voltage dropped after the pump shut off, confirming internal leakage in the ABS brake actuator assembly. CORRECTION Remove and replace ABS brake actuator assembly. Perform actuator initialization and brake-system bleed. Clear brake DTCs.

CUSTOMER CONCERN Customer states the engine will not start and DTC P0351 returns immediately after clearing. CAUSE Lab-scope testing of the IGT command and IGF feedback circuits confirmed a failed ignition-coil assembly. CORRECTION Remove and replace failed ignition-coil assembly. Clear DTC P0351 and verify normal starting operation.

CUSTOMER CONCERN Customer states the engine-temperature reading fluctuates while driving and DTC P0117 returns after coolant-temperature sensor replacement. CAUSE The 5-volt reference and warmed-up sensor signal tested correctly, confirming the radiator was not maintaining stable coolant temperature. CORRECTION Remove and replace radiator. Refill and bleed engine cooling system, clear DTC P0117 and verify stable coolant temperature.

CUSTOMER CONCERN Customer states the engine overheats while driving and the heater blows cold. Coolant temperature reaches approximately 230°F with the cooling fans operating. CAUSE Cooling-system bleeding and flow checks confirmed combustion leakage from a failed cylinder-head gasket. CORRECTION Remove and replace failed cylinder-head gasket. Refill and bleed engine cooling system and verify normal operating temperature.