Neutral Position Switch Signal Circuit Troubleshooting
Neutral Position Switch Signal Circuit TroubleshootingM/T:
1. Turn the ignition switch ON (II).
2. Shift the transmission to 1st gear.
3. Measure voltage between ECM connector terminal B12 and body ground.
Is there battery voltage?
YES - Go to step 4.
NO - Go to step 6.
4. Shift the transmission to N position.
5. Measure voltage between ECM connector terminal B12 and body ground.
Is voltage less than 1.0 V?
YES - The neutral position switch signal is OK.
NO - Go to step 16.
6. Turn the ignition switch OFF.
7. Disconnect the neutral position switch 2P connector.
8. Turn the ignition switch ON (II).
9. Measure voltage between ECM connector terminal B12 and body ground.
Is there battery voltage?
YES - Replace the neutral position switch.
NO - Go to step 10.
10. Turn the ignition switch OFF.
11. Wait for 1 minute. If the radiator fan is running, wait for minute after radiator fan stops.
12. Disconnect ECM connector B (24P).
13. Check for continuity between ECM connector terminal B12 and body ground.
Is there continuity?
YES - Go to step 14.
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
14. Disconnect the EPS control unit 20P connector.
15. Check for continuity between ECM connector terminal B12 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (B12), the EPS control unit, and the neutral position switch.
NO - Substitute a known-good EPS control unit and recheck.
16. Turn the ignition switch OFF.
17. Disconnect the neutral position switch 2P connector.
18. Check for continuity between neutral position switch 2P connector terminals No.1 and No.2 with the transmission in 1st gear.
Is there continuity?
YES - Replace the neutral position switch.
NO - Go to step 17.
19. Turn the ignition switch ON (II).
20. Measure voltage between neutral position switch terminal No.2 and body ground.
Is there battery voltage?
YES - Repair open in the wire between the neutral position switch and G1O1.
NO - Repair open in the wire between the ECM (B12) and the neutral position switch.