Diagnostic Chart

1. Check voltage between terminals PR and E2 of ABS & TRAC ECU connector. Remove air cleaner and duct. Remove A.B.S. & TRAC ECU with connectors still connected. Run engine for about 30 seconds at idle speed to raise the pressure of the TRAC actuator to a high level. Stop engine and then turn ignition switch ON. Measure voltage between terminals PR and E2 of ABS & TRAC ECU connector. About 5V should be present. Drain the fluid out of the actuator to reduce the pressure. Measure voltage between terminals PR and E2 of A.B.S. & TRAC ECU connector. No voltage should exist. Add fluid to reservoir after the check. If voltage is correct, check and replace ABS & TRAC ECU. If voltage is not correct, go to next step.
2. Check pressure switch. Disconnect pressure switch connector. Measure resistance between terminals 1 and 2 of pressure switch connector. There should be no resistance.

Connect pressure switch connector. Run engine for about 30 seconds at idle speed to raise the pressure of the TRAC actuator to a high level. Stop the engine and then turn ignition switch ON. Measure resistance between terminals 1 and 2 of pressure switch connector. Resistance should be appx. 1.5 Ohms. If switch is not okay, replace TRAC actuator. If switch is okay, go to next step.

3) Check harness and connector between ABS & TRAC ECU and TRAC actuator. Repair or replace any faulty connectors or harnesses. If connectors are okay, check and replace ABS & TRAC ECU.