Inspection Procedure 1

INSPECTION PROCEDURE 1: Power is not turned ON when the power switch is turned ON.

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














OPERATION

When the ignition switch is in the ON or ACC position, the radio and CD player power can be turned ON. With the radio and CD player power ON, when the ignition switch is turned to the OFF position, the power for radio and CD player 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 cannot be turned ON, the radio and CD player, or power supply circuit for radio and CD player may have a problem, or the option coding information may be inconsistent.

PROBABLE CAUSES

- Malfunctions of radio and CD player
- 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

STEP 1. ETACS-ECU coding data check.

(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) Reading and Clearing Diagnostic Trouble Codes."

(2)Operate scan tool MB991958 to read the ETACS-ECU option coding information. Programming and Relearning.)

(3)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 Electronic Time and Alarm Control System (ETACS)), and then go to Step 3.
NO Go to Step 3.
STEP 3. Using scan tool MB991958, check data list.

Check if ETACS-ECU related signal is set.

- Turn the ignition switch to the ON position.
- selector lever is "R" (Reverse) position





OK: Normal condition is displayed.


Q. Is the check result normal?

YES Go to step 8.
NO Go to step 4.
STEP 4. Check radio and CD player connector C-103 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is radio and CD player connector C-103 in good condition?

YES Go to Step 5.
NO Repair or replace the damaged component(s). Harness Connector Inspection.
STEP 5. Check the power supply circuit to the radio and CD player.
Measure the voltage at radio and CD player connector C-103.

(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 approximately 12 volts (battery positive 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 connector C-103 (terminal 30).

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

NOTE:
Also check joint connector C-102 and ETACS-ECU connector C-406, C-417 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-102 or ETACS-ECU connector C-406, C-417 are damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between fusible link (36) and radio and CD player connector C-103 (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 that the radio and CD player is correctly grounded

The radio and CD player should be connected to the ground with an assembling screw.

Q. Is the radio and CD player correctly grounded?

YES Go to Step 8.
NO Securely install and ground the radio and CD player.
STEP 8. Retest the system

Check if the radio and CD player power is turned ON.

Q. Is the check result normal?

YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the radio and CD player.