W/Harness Inspection

4WD Control
U0121 Lost Communication With Anti-Lock Brake System (ABS) Control Module - Inspection/Repair:_:W/Harness Inspection

Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration,or damage.
3. Has a problem been found?





CAN communication circuit inspection (ABS ECM <-> 4WD ECM)
1. Ignition "OFF"
2. Disconnect 4WD ECM connector and ABS ECM connector
3. Measure the resistance between CAN-HIGH terminal of 4WD ECM harness connector and CAN-HIGH terminal of ABS ECM harness connector.
4. Measure the resistance between CAN-LOW terminal of 4WD ECM harness connector and CAN-LOW terminal of ABS ECM harness connector.

Specification :below 1Ohms




5. Is the measured resistance within specification ?