Electrical Power Steering (EPS) Signal Circuit Troubleshooting
Electrical Power Steering (EPS) Signal Circuit Troubleshooting1. Start the engine, and let it idle.
2. Align the steering wheel straight ahead.
3. Check the EPS SIGNAL in the DATA LIST with the HDS.
Does it indicate LOW?
YES - Go to step 4.
NO - Go to step 6.
4. Turn the steering wheel quickly to the full lock position.
5. Check the EPS SIGNAL in the DATA LIST with the HDS.
Does it change to HIGH?
YES - The EPS signal circuit is OK.
NO - Go to step 12.
6. Turn the ignition switch OFF.
7. Jump the SCS line with the HDS.
8. Disconnect PCM connector E (31P).
9. Disconnect EPS control unit 13P connector.
10. Connect PCM connector terminal E17 to body ground with a jumper wire.
11. Check for continuity between EPS control unit 13P connector terminal No. 13 and body ground.
Is there continuity?
YES - Substitute a known-good EPS control unit, and recheck.
NO - Repair open in the wire between the PCM (E17) and the EPS control unit.
12. Turn the ignition switch OFF.
13. Disconnect EPS control unit 13P connector.
14. Turn the ignition switch ON (II).
15. Measure voltage between PCM connector terminals A3 and E17.
Is there battery voltage?
YES - Substitute a known-good EPS control unit, and recheck.
NO - Go to step 16.
16. Turn the ignition switch OFF.
17. Jump the SCS line with the HDS.
18. Disconnect PCM connector E (31P).
19. Check for continuity between PCM connector terminal E17 and body ground.
Is there continuity?
YES - Repair short in the wire between the PCM (E17) and the EPS control unit
NO - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.