Diesel Data: Automotive Repair

Symptom Troubleshooting




Symptom Troubleshooting: Audio unit power switch will not turn on (No information display and no sound)

Audio unit power switch will not turn on (No information display and no sound) (with navigation)

NOTE:

- Check the vehicle battery condition first.

- Check the connectors for poor connections or loose terminals.

1. With the ignition switch ON (II), push the power switch ON to see if the audio-navigation unit turns on.

Does the audio-navigation unit display operate properly, and does the audio sound normal?
YES - Intermittent failure, the system is OK at this time.

NO - Go to step 2.


2. Turn the ignition switch to LOCK (0).

3. Check the No. 1 (7.5 A) fuse and the No. 14 (7.5 A) fuse in the under-dash fuse/relay box and the No. 1 (30 A) fuse (auxiliary under-dash fuse box) on the wire harness near the under-dash fuse/relay box.

Are the fuses OK?
YES - Go to step 4.

NO - Replace the fuse(s), and recheck.


4. Remove the audio-navigation unit. Audio-Navigation Unit Removal/Installation (With Navigation) Check that the audio-navigation unit is properly connected.

Is it connected properly?
YES - Go to step 5.

NO - Reconnect the connectors, and recheck the function.


5. Disconnect audio-navigation unit connector A (24P) and connector C (8P).
NOTE: Eject all the CDs before removing the audio-navigation unit to prevent damaging the CD player's loading mechanism.

6. Turn the ignition switch to ON (II).

7. Measure the voltage between audio-navigation unit connector A (24P) terminal No. 14 and body ground, and between terminal No. 24 and body ground, and audio-navigation unit connector C (8P) terminal No. 1 and body ground.

Is there battery voltage on both terminals?
YES - Go to step 8.

NO - Repair open in the wire(s) between the No. 1 (7.5 A) fuse and the No. 14 (7.5 A) in the under-dash fuse/relay box and the No. 1 (30 A) fuse (auxiliary under-dash fuse box) on the wire harness near the under-dash fuse/relay box and the audio unit.










8. Turn the ignition switch to LOCK (0).

9. Reconnect navigation unit connector A (24P) and connector C (8P).

10. Measure the voltage between audio-navigation unit connector A (24P) terminal No. 12 and body ground, between audio-navigation unit connector C (8P) terminal No. 4 and body ground, and between audio-navigation unit connector B (24P) terminal No. 17 and body ground.

Is there less than 0.1 V on all terminals?
YES - Replace the audio-navigation unit. Audio-Navigation Unit Removal/Installation (With Navigation)

NO - There is an open or high resistance in the wire between audio-navigation unit connector A (24P) terminal No. 12 or audio-navigation unit connector B (24P) terminal No. 17 and body ground (G503 and G502), or navigation connector C (8P) and body ground (G503).