Operation CHARM: Car repair manuals for everyone.

Inspection Procedure 1

Inspection Procedure 1: Power Is Not Turned ON When The Power Switch Is Turned ON.

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

Radio And CD Player Or CD Changer Power Supply Circuit (Part 1):




Radio And CD Player Or CD Changer Power Supply Circuit (Part 2):






OPERATION
When the ignition switch is in the ON or ACC position, the radio and CD player or CD changer power can be turned ON. With the radio and CD player or CD changer power ON, when the ignition switch is turned to the OFF position, the power for radio and CD player or CD changer is also turned OFF.

COMMENTS ON TROUBLE SYMPTOM
Provided that the audio diagnostic trouble code is not set, if the power for radio and CD player or CD changer cannot be turned ON, the radio and CD player or CD changer, or power supply circuit for radio and CD player or CD changer may have a problem, or the option coding information may be inconsistent.

PROBABLE CAUSES
- Malfunctions of radio and CD player or CD changer
- Malfunction of the ETACS-ECU
- Option coding information inconsistency
- 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. ETACS-ECU coding data check.




1. Operate scan tool MB991958 to read the ETACS-ECU option coding information (Refer to general (Body and Chassis) Coding List.).
2. Check that the "AUDIO" is set to "Present".

Q: Is the check result normal?

YES : Go to Step 2.

NO : Operate scan tool MB991958 to set the option coding "AUDIO" to "Present", and check the trouble symptom.

STEP 2. 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 Diagnosis. Diagnostic Trouble Code Descriptions

NO : Go to Step 3.

STEP 3. 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 4.

NO : Refer to Troubleshooting Inspection Procedure 1 "The ignition switch (ACC) signal is not received". Inspection Procedure 1

STEP 4. Check radio and CD player or CD changer connector C-16 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is radio and CD player or CD changer connector C-16 in good condition?

YES : Go to Step 5.

NO : Repair or replace the damaged component(s). Refer to general (electrical) Harness Connector Inspection. The steering remote control switch should work normally.

STEP 5. Check the power supply circuit to the radio and CD player or CD changer. Measure the voltage at radio and CD player or CD changer connector C-16.

1. Disconnect the connector, and measure at the wiring harness-side connector.




2. Measure the voltage between terminal 30 and ground.

OK: The voltage should measure approximately 12 volts (battery positive voltage).

Q: Is the measured voltage battery voltage?

YES : Go to Step 7.

NO : Go to Step 6.

STEP 6. Check the wiring harness between fusible link 36 and radio and CD player or CD changer connector C-16 (terminal 30).

- Check the power supply lines (battery power supply) for open circuit and short circuit.

Q: Is the wiring harness between fusible link 36 and radio and CD player or CD changer connector C-16 (terminal 30) 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 the wiring harness between ETACS-ECU connector C-309 (terminal 2) and fusible link (37)

NOTE: Also check ETACS-ECU connector C-307, C-317 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-307, C-317 is damaged, repair or replace the connector as described in general (electrical), Harness Connector Inspection.

- 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 8.

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 8. 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 9.

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

STEP 9. Retest the system

Check if the radio and CD player or CD changer 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 radio and CD player or CD changer.