Inspection Procedure I-8

The High-beam Indicator Light does not Illuminate.

Connectors:

Headlight circuit
- Refer to Inspection Procedure I-2.

TECHNICAL DESCRIPTION (COMMENT)
If the high-beam indicator light does not illuminate, the high-beam indicator light bulb or the ETACS-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the high-beam indicator light bulb
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Test Harness Set

STEP 1. Check the headlight operation.

Q: Do the headlights illuminate?

YES: Go to Step 2.

NO: Repair the headlights first.




STEP 2. Check at ETACS-ECU connector C-94 in order to check the high-beam indicator light circuit.
1. Disconnect ETACS-ECU connector C-94, and measure at the wiring harness side.
2. Turn the ignition switch to the "ON" position.
3. Connect terminal No.72 to ground.

Q: Does the high-beam indicator light illuminate?

YES: Replace the ETACS-ECU. Check that the high-beam indicator light illuminates normally.

NO: Go to Step 3.




STEP 3. Check high-beam indicator light bulb.

Q: Is the high-beam indicator light bulb in good condition?

YES: Go to Step 4.

NO: Replace the high-beam indicator light bulb. Check that the high-beam indicator light illuminates normally.




STEP 4. Check the combination meter (printed-circuit board).
1. Remove the combination meter.
2. Remove the high-beam indicator light bulb. Then measure the resistance value between the bulb terminals.
3. Install the bulb to the combination meter, and then measure the resistance value between connector C-29 terminals 22 and 23. The measured resistance value should be roughly the same as the value measured in Step (2).

Q: Are these two resistance values extremely different?

YES: Repair or replace the combination meter (printed circuit board). Check that the headlight-beam indicator light illuminates normally.

NO: (roughly the same) : Go to Step 5.




STEP 5. Check combination meter connector C-29 in order to check the fusible link (1) line of the power supply to the high-beam indicator light.
1. Disconnect combination meter connector C-29, and measure at the wiring harness side.
2. Measure the voltage between terminal 23 and ground.
- The measurement value should be 12 volts.

Q: Does the measured voltage correspond with this range?

YES: Go to Step 8.

NO: Go to Step 6.




STEP 6. Check combination meter connector C-29 for damage.

Q: Is combination meter connector C-29 in good condition?

YES: Go to Step 7.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the high-beam indicator light illuminates normally.










STEP 7. Check the wiring harness between combination meter connector C-29 and fusible link (1).

NOTE: Also check junction block connectors C-88, C-89 and intermediate connector C-66. If junction block connectors C-88, C-89 or intermediate connectors C-66 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q: Is the wiring harness between combination meter connector C-29 and fusible link (1) in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the high-beam indicator light illuminates normally.







STEP 8. Check combination meter connector C-29 and ETACS-ECU connector C-94 for damage.

Q: Are combination meter connector C-29 and ETACS-ECU connector C-94 in good condition?

YES: Go to Step 9.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the high-beam indicator light illuminates normally.







STEP 9. Check the wiring harness between combination meter connector C-29 and ETACS-ECU connector C-94.

Q: Is the wiring harness between combination meter connector C-29 and ETACS-ECU connector C-94 in good condition?

YES: No action to be taken.

NO: Repair the wiring harness. Check that the high-beam indicator light illuminates normally.