Abs Does Not Operate
CAUTION:
If ABS ECU replacement is necessary during testing, always ensure ABS ECU connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ABS ECU malfunction.
Retrieve Diagnostic Trouble Codes (DTC). See RETRIEVING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. Ensure a normal code is output. Check ignition power supply circuit. See DTC 41: IGNITION POWER SUPPLY CIRCUIT under DIAGNOSTIC TESTS. Check speed sensor circuits. See DTC 31-34: SPEED SENSOR CIRCUIT under DIAGNOSTIC TESTS. Check ABS actuator. See ABS ACTUATOR CHECK under COMPONENT TESTS. If ABS actuator is okay, check hydraulic system for leaks. See Fig 1. If all listed items test okay, replace ABS ECU.