Mode Control Motor Troubleshooting

Mode Control Motor Circuit Troubleshooting
1. Check the No.16 (7.5 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 2.

NO - Replace the fuse, and recheck.

2. Disconnect the mode control motor 7P connector.
3. Turn the ignition switch ON (II).





4. Measure the voltage between the No.1 terminal of the mode control motor 7P connector and body ground.

Is there battery voltage?

YES - Go to step 5.

NO - Repair open in the wire between the mode control motor and the No.16 fuse in the under-dash fuse/relay box.

5. Turn the ignition switch OFF.
6. Test the mode control motor.

Is the mode control motor OK?

YES - Go to step 7.

NO - Go to step 12.

7. Disconnect the heater control panel connector B (22P).





8. Check for continuity between the No.6, 9, 10, 20, 21 and No.22 terminals of the heater control panel connector B (22P) and body ground individually.

Is there continuity?

YES - Repair short to body ground in the wire(s) between the heater control panel and the mode control motor.

NO - Go to step 9.





9. Turn the ignition switch ON(II), and check the same terminals for voltage.

Is there any voltage?

YES - Repair short to power in the wire between the heater control panel and the mode control motor. This short also damages the heater control panel. Repair the short to power before replacing the heater control panel.

NO - Go to step 10.

10. Turn the ignition switch OFF.





11. Check for continuity between the following terminals of the heater control panel connector B (22P) and the mode control motor 7P connector.

22P: 7P:
No.6 No.7
No.9 No.6
No.10 No.5
No.20 No.2
No.21 No.3
No.22 No.4

Is there continuity?

YES - Check for loose wires or poor connections at the heater control panel connector B (22P) and at mode control motor 7P connector. If the connections are good, substitute a known-good heater control panel, and recheck. If the symptom/indication goes away, replace the original heater control panel.

NO - Repair open in the wire(s) between the heater control panel and the mode control motor.

12. Remove the mode control motor.
13. Check the mode control linkage and doors for smooth movement.

Do the mode control linkage and doors move smoothly?

YES - Replace the mode control motor.

NO - Repair the mode control linkage or doors.