Display Unit Buttons Do Not Work

1. Turn the ignition switch to ACC (I).




2. Measure the voltage between body ground and display unit connector B (20P) terminals No. 1 and No. 2 individually.

Is there battery voltage?

YES - Go to step 3.

NO - If the +8 wire does not have voltage, repair open in the wire between the passenger's under- dash fuse/relay box and the display unit.

If the ACC wire does not have voltage, repair open in the wire between the driver's under-dash fusel relay box and the display unit.




3. Check for continuity between display unit connector B (20P) terminal No. 10 and body ground.

Is there continuity?

YES - Go to step 4.

NO - Repair open in the wire between the display unit and body ground (G401).

4. Turn the ignition switch OFF.
5. Disconnect the navigation unit and display unit connectors.




6. Check for continuity between body ground and display unit connector B (20P) terminals No. 5 and No. 15 individually.

Is there continuity?

YES - There is a short to body ground in the circuit between the display unit and the navigation unit. Replace the affected shielded harness.

NO - Go to step 7.




7. Check for continuity between display unit connector B (20P) terminal No. 5 and navigation unit connector B (16P) terminal No. 7.

Is there continuity?

YES - Go to step 8.

NO - There is an open in the circuit between the display unit and the navigation unit. Replace the affected shielded harness.




8. Check for continuity between display unit connector B (20P) terminal No. 15 and navigation unit 16P connector B(16P) terminal No. 15

Is there continuity?

YES - Replace the display unit.

NO - There is an open in the circuit between the display unit and the navigation unit. Replace the affected shielded harness.