Inspection Procedure 4

Inspection Procedure 4: The Navigation System can be Operated while the Vehicle is Driven.

CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Audio Visual Navigation Unit Communication Circuit:

COMMENTS ON TROUBLE SYMPTOM
There is a failure in the wiring harness between the combination meter and the audio visual navigation unit, the respective connector(s), the combination meter or the audio visual navigation unit.

PROBABLE CAUSES
- Malfunctions of combination meter
- Malfunctions of audio visual navigation unit
- Damaged harness wires and connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

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. Service Mode

Q: Is the vehicle speed signal transmitted normally?

YES : Replace the audio visual navigation unit.

NO : Go to Step 2.

STEP 2. Check the speedometer.

Check whether the speedometer works normally.

Q: Does the speedometer work normally?

YES : Go to Step 3.

NO : Diagnose the combination meter (Refer to Combination meter Troubleshooting). Symptom Chart

STEP 3. Check combination meter connector C-04 and audio visual navigation unit connector C-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is combination meter connector C-04 and audio visual navigation unit connector C-14 in good condition?

YES : Go to Step 4.

NO : Repair or replace the damaged component (Refer to general (electrical), Harness Connector Inspection).

STEP 4. Check the wiring harness between combination meter connector C-04 (terminal 20) and audio visual navigation unit connector C-14 (terminal 13).

- Check the communication lines for open circuit.

NOTE: Also check joint connector C-03 and intermediate connector C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-03 or intermediate connector C-105 is damaged, repair or replace the connector as described in general (electrical), Harness Connector Inspection.

Q: Is the wiring harness between combination meter connector C-04 (terminal 20) and audio visual navigation unit connector C-14 (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.

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.