CUSTOMER CONCERN The brake pedal is hard and DTCs C1253 and C1256 are stored after body repairs. CAUSE Rodent damage opened the brake-booster pump wiring at its connector, interrupting power to the ABS hydraulic modulator/pump assembly. CORRECTION Repair the rodent-damaged brake-booster pump wiring at the connector, clear DTCs C1253 and C1256, and verify normal brake operation.

CUSTOMER CONCERN After engine-harness replacement, the skid-control ECU stores DTCs C1252, C1253, C1256, and C1345. CAUSE The skid-control ECU with actuator failed after the brake-booster pump power, ground, and direct-operation checks. CORRECTION Remove and replace the failed skid-control ECU with actuator.

CUSTOMER CONCERN ABS and traction-control warning lamps remain on after body repairs with DTCs C1253, C1256, and C1345. CAUSE Battery feeds and fuses to skid-control ECU connector A28 were verified, confirming an internal failure of the skid-control ECU with actuator; the brake-booster pump could not operate for linear-valve learning. CORRECTION Remove and replace the skid-control ECU with actuator, perform the automated brake bleed and linear-valve offset calibration, clear

CUSTOMER CONCERN The brake pedal is hard after body repairs and DTCs C1253 and C1256 are stored. CAUSE Power-supply checks isolated the fault to the brake master-cylinder/skid-control hydraulic assembly rather than the ABS MTR No. 1 and No. 2 feeds. CORRECTION Remove and replace the failed brake master-cylinder assembly, perform the required brake-system bleed and calibration procedures, clear DTCs C1253 and C1256, and verify normal brake assist.

CUSTOMER CONCERN ABS warning is on with C1252, C1253, and C1256; after replacement of a melted ABS motor relay, C1256 continues to report low accumulator pressure. CAUSE The ABS actuator pump could not build and maintain normal accumulator pressure after relay power was restored, confirming an internal actuator failure. CORRECTION Remove and replace the ABS actuator assembly, bleed the brake system, clear DTCs, and verify accumulator pressure and brake-assist operation.

CUSTOMER CONCERN Brake-system warning remains after collision repair and C1253 is stored. CAUSE Accumulator-pressure data rose to 3.7 volts while the pump ran, then continuously dropped to 3.1 volts and restarted the pump, confirming the ABS pump could not maintain hydraulic pressure. CORRECTION Remove and replace the ABS pump motor assembly, clear DTC C1253, and verify accumulator pressure and brake-assist operation.

CUSTOMER CONCERN Following collision repairs and replacement of the brake-booster pump, DTCs C1252, C1253, C1256, C1345 and C1465 remain stored. CAUSE Accumulator pressure was low because air remained in the electronically controlled brake hydraulic system. CORRECTION Perform the scan-tool-assisted brake bleeding procedure, clear C1252, C1253, C1256, C1345 and C1465, and verify accumulator pressure and brake operation.

CUSTOMER CONCERN After replacement of a burned engine wiring harness, the skid-control ECU stores C1252, C1253, C1256 and C1345. CAUSE Power and ground testing isolated the remaining brake-system fault to a failed skid-control ECU with actuator. CORRECTION Remove and replace the skid-control ECU with actuator, clear C1252, C1253, C1256 and C1345, and verify electronically controlled brake operation.

CUSTOMER CONCERN The ABS relays click rapidly after an incorrect brake-bleeding attempt, and DTCs C1253 and C1256 are stored. CAUSE Power, ground, and communication checks confirmed an internal failure of the skid-control electronic control unit. CORRECTION Remove and replace the failed skid-control electronic control unit.