Electrical Power Steering (EPS) Signal
Electrical Power Steering (EPS) Signal Circuit Troubleshooting1. Turn the ignition switch ON (II).
2. Measure voltage between ECM connector terminals A26 and B20.
Is there battery voltage?
YES - Go to step 6.
NO - Go to step 3.
3. Start the engine.
4. Turn the steering wheel to the full lock position.
5. Measure voltage between ECM connector terminals A26 and B20.
Is there battery voltage momentarily?
YES - The EPS signal is OK.
NO - Go to step 10.
6. Turn the ignition switch OFF.
7. Disconnect the EPS control unit 14P connector.
8. Turn the ignition switch ON (II).
9. Measure voltage between the EPS control unit terminal No.13 and body ground.
Is there battery voltage?
YES - Substitute a known-good EPS control unit and recheck.
NO - Repair open in the wire between the ECM (A26) and the EPS control unit.
10. Turn the ignition switch OFF.
11. Disconnect the EPS control unit 14P connector.
12. Turn the ignition switch ON (II).
13. Measure voltage between EPS control unit terminal No.13 and the body ground.
Is there battery voltage?
YES - Substitute a known-good EPS control unit and recheck.
NO - Go to step 14.
14. Turn the ignition switch OFF
15. Disconnect ECM connector A (32P).
16. Check for continuity between body ground and ECM connector terminal A26.
Is there continuity?
YES - Repair short in the wire between the ECM (A26) and the EPS control unit.
NO - Substitute a known-good ECM and recheck. If prescribed voltage is now available, replace the original ECM.