Inspection Procedure M-1

Dome Light Drive Circuit:

Connectors:

CIRCUIT OPERATION
The dome light dimming function and the keyless entry system answerback function illuminate the dome light when the dome light switch is at "door control operation position."

TECHNICAL DESCRIPTION (COMMENT)
If the dome light does not illuminate at all, the dome light bulb may be burned out, or the power supply circuit or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the dome light
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tool:
MB991223: Test Harness Set

STEP 1. Check the trouble symptom.
If the dome light illuminates when the dome light switch is set to "ON" position, go to Step 2.
If the dome light does not illuminate at all switch positions, go to Step 4.







STEP 2. Check the dome light connector D-03 or D-04 and ETACS-ECU connector C-114 for damage.
If the dome light connector D-03 or D-04 and ETACS-ECU connector C-114 are damaged, repair or replace them. Refer to Harness Connector Inspection. The dome light should illuminate.
If the connectors are in good condition, go to Step 3.

STEP 3. Check the harness wires between dome light connector D-03 or D-04 and ETACS-ECU connector C-114.

NOTE: After checking junction block connector C-103, check the wires. If junction block connector C-103 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between dome light connector D-03 or D-04 and ETACS-ECU connector C-114 are damaged, repair them. The dome light should illuminate.
If the harness wires are in good condition, replace the ETACS-ECU.
The dome light should illuminate.

STEP 4. Check the dome light bulb.
If the dome light bulb has blown, replace it.
The dome light should illuminate.
If the dome light bulb has not blown, go to Step 5.

STEP 5. Check the dome light power supply at the dome light connector D-03 or D-04 .
1. Disconnect the dome light connector D-03 or D-04 and measure at the harness side.
2. Voltage between terminal 2 or 3 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
If not approximately 12 volts, go to Step 6.
If approximately 12 volts, replace the dome light.
The dome light should illuminate.

STEP 6. Check the dome light connector D-03 or D-04 for damage.
If the dome light connector D-03 or D-04 is damaged, repair or replace it. Refer to Harness Connector Inspection.
The dome light should illuminate.
If the connector is in good condition, go to Step 7.

STEP 7. Check the harness wires between dome light connector D-03 or D-04 and battery.

NOTE: After checking junction block connector C-103 and C-109, joint connector C-78 and intermediate connector C-89, check the wires. If junction block connector C-103 and C-109, joint connector C-78 and intermediate connector C-89 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If the harness wires between dome light connector D-03 or D-04 and battery are damaged, repair them.
The dome light should illuminate.