Inspection Procedure 4: The navigation system can be operated while the vehicle is driven.: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Perform "Vehicle Signal Check" in the MMCS service mode. 

   Perform "Vehicle Signal Check" in the MMCS service mode to check whether vehicle speed signal is normal (Refer to SERVICE MODE  ).

   Q: Is the vehicle speed signal transmitted normally? 

   YES:  Replace the audio visual navigation unit.

   NO:  Go to Step 2.

2. STEP 2. Check the speed meter. 

   Check whether the speedometer works normally.

   Q: Does the speed meter work normally? 

   YES:  Go to Step 3.

   NO:  Diagnose the combination meter. Refer to DIAGNOSTIC TROUBLE CODE CHART .

3. STEP 3. Check combination meter connector C-03 and audio visual navigation unit connector C-10 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is combination meter connector C-03 or audio visual navigation unit connector C-10 in good condition? 

   YES:  Go to Step 4.

   NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .

4. STEP 4. Check the wiring harness between combination meter connector C-03 (terminal 20) and audio visual navigation unit connector C-10 (terminal 13). 
   • Check the communication lines for open circuit.
     NOTE: Also check intermediate connector C-17 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-17 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .

   Q: Is the wiring harness between combination meter connector C-03 (terminal 20) and audio visual navigation unit connector C-10 (terminal 13) in good condition? 

   YES:  Go to Step 5.

   NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

5. STEP 5. Substitute a known good audio visual navigation unit, and check the trouble symptom. 

   Check that no menus are active during driving.

   Q: Is the check result normal? 

   YES:  Replace the audio visual navigation unit.

   NO:  Replace the combination meter.