Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Navigation Communication Line Circuit Troubleshooting

NAV. Communication Line Circuit Troubleshooting

1. Disconnect navigation unit connector A (20P).
2. Disconnect the climate control unit 30P connector.




3. Check for continuity between the above terminals of the climate control unit 30P connector and navigation unit connector A (20P).

Is there continuity?

YES - Go to step 4.

NO - Repair any open in the wire(s) between the climate control unit and the navigation unit.




4. Check for continuity between body ground and the climate control unit 30P connector terminals No. 6, 17 and 24 individually.

Is there continuity?

YES - Repair any short to body ground in the wire(s) between the climate control unit and the navigation unit.

NO - Check for loose wire or poor connections at the climate control unit 30P connector and at the navigation unit connector A (20P). If the connections are good, substitute a known-good climate control unit and/or navigation unit, and recheck. If the symptom/indication goes away, replace the original climate control unit and/or navigation unit.