Abs Does Not Operate

CAUTION: If Anti-Lock Brake System/Traction Control/Vehicle Skid Control Electronic Control Unit (ABS/TRAC/VSC ECU) replacement is necessary during testing, always ensure ABS/TRAC/VSC ECU connectors and ground circuit are okay. If either is suspect, repair and repeat testing to confirm ABS/TRAC/VSC ECU malfunction.

Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. If any DTCs are present, perform appropriate diagnostic test. If no DTCs are present, check IG1 power source circuit. See DTC C1241/41: IG1 POWER SUPPLY CIRCUIT under DIAGNOSTIC TESTS. Check speed sensor circuit. Perform appropriate wheel speed sensor circuit test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION table under DIAGNOSIS & TESTING. Check hydraulic brake booster. See HYDRAULIC BRAKE BOOSTER CHECK under COMPONENT TESTS. If hydraulic brake booster is not okay, check hydraulic system for leakage and repair as necessary. If all preceding tests are okay, replace ABS/TRAC/VSC ECU.