Inspection Procedure 1
Inspection Procedure 1: No Navigation Screen is Displayed.CAUTION: Before replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
Audio Visual Navigation Unit Power Supply Circuit (Part 1):
Audio Visual Navigation Unit Power Supply Circuit (Part 2):
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. Check audio visual navigation unit connector C-14 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio visual navigation unit connector C-14 in good condition?
YES : Go to Step 2.
NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection.
STEP 2. Check the ground circuit to the audio visual navigation unit connector. Measure the resistance at audio visual navigation unit connector C-14.
1. Disconnect audio visual navigation unit connector C-14, and measure the resistance available at the wiring harness side of the connector.
2. Measure the resistance between terminal 9 and ground.
OK: The resistance should be 2 ohms or less
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 4.
NO : Go to Step 3.
STEP 3. Check the wiring harness between audio visual navigation unit connector C-14 (terminal 9) and ground.
- Check the ground wires for open circuit.
NOTE: Also check intermediate connector C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If 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 audio visual navigation unit connector C-14 (terminal 9) and ground in good condition?
YES : The trouble can be an intermittent malfunction (Refer to general (Body and Chassis) How to use Troubleshooting/inspection Service Points, How to Cope with Intermittent Malfunction).
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 4. Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code.
Check if the diagnostic trouble code is set to the ETACS-ECU.
Q: Is the DTC set?
YES : Troubleshoot the ETACS-ECU. Refer to Chassis electrical Diagnosis. Diagnostic Trouble Code Descriptions
NO : Go to Step 5.
STEP 5. Check ETACS-ECU connector C-317 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-317 in good condition?
YES : Go to Step 6.
NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection.
STEP 6. Check the wiring harness between ETACS-ECU connector C-317 (terminal 1) and audio visual navigation unit connector C-14 (terminal 17).
- Check the power supply lines (battery supply) for open circuit.
NOTE: Also check intermediate connector C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-15 is damaged, repair or replace the connector as described in general (electrical), Harness Connector Inspection.
Q: Is the wiring harness between ETACS-ECU connector C-317 (terminal 1) and audio visual navigation unit connector C-14 (terminal 17) in good condition?
YES : Go to Step 7.
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 7. Check audio visual navigation unit connector C-13 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is audio visual navigation unit connector C-13 in good condition?
YES : Go to Step 8.
NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection.
STEP 8. Check the wiring harness between ETACS-ECU connector C-317 (terminal 1) and audio visual navigation unit connector C-13 (terminal 21).
- Check the power supply lines (battery supply) for open circuit.
NOTE: Also check intermediate connector C-103 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-103 is damaged, repair or replace the connector as described in general (electrical), Harness Connector Inspection .
Q: Is the wiring harness between ETACS-ECU connector C-317 (terminal 1) and audio visual navigation unit connector C-13 (terminal 21) in good condition?
YES : Go to Step 9.
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 9. Using scan tool MB991958, check data list.
Check the input signal of ACC relay.
- Turn the ignition switch to the ACC position.
OK: Normal condition is displayed.
Q: Is the check result normal?
YES : Go to Step 10.
NO : Refer to Chassis electrical ETACS, Diagnosis Inspection Procedure 1 "The ignition switch (ACC) signal is not received." Inspection Procedure 1
STEP 10. Check ETACS-ECU connector C-309 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-309 in good condition?
YES : Go to Step 11.
NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection. The steering remote control switch should work normally.
STEP 11. Check the power supply circuit to the ETACS-ECU. Measure the voltage at ETACS-ECU connector C-309.
1. Disconnect the connector, and measure at the wiring harness-side connector.
2. Turn the ignition switch to the "ACC" position.
3. Measure the voltage between terminal 2 and ground.
OK: Battery voltage
Q: Is the measured voltage battery voltage?
YES : Go to Step 13.
NO : Go to Step 12.
STEP 12. Check the wiring harness between ETACS-ECU connector C-309 (terminal 2) and fusible link (37)
- Check the power supply line for open circuit and short circuit.
Q: Is the wiring harness between ETACS-ECU connector C-309 (terminal 2) and fusible link (37) in good condition?
YES : Go to Step 13.
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 13. Check ETACS-ECU connector C-315 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Is ETACS-ECU connector C-315 in good condition?
YES : Go to Step 14.
NO : Repair or replace the damaged component(s). Refer to general (electrical), Harness Connector Inspection. The steering remote control switch should work normally.
STEP 14. Check the wiring harness between audio visual navigation unit connector C-14 (terminal 14) and ETACS-ECU connector C-315 (terminal 9).
- Check the power supply line for open circuit.
NOTE: Also check joint connector C-07 and intermediate connector C-105 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-07 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 audio visual navigation unit connector C-14 (terminal 14) and ETACS-ECU connector C-315 (terminal 9) in good condition?
YES : Go to Step 15.
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 15. Retest the system
Check if the audio visual navigation unit power is turned ON.
Q: Is the check result normal?
YES : The trouble can be an intermittent malfunction (Refer to general (Body and Chassis) How to use Troubleshooting/inspection Service Points How to Cope with Intermittent Malfunction).
NO : Replace the audio visual navigation unit.