Inspection Procedure I-8
The High-beam Indicator Light does not IlluminateHi-beam Indicator Light Circuit:
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-228 in order to check the high-beam indicator light circuit
1. Disconnect ETACS-ECU connector C-228, 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 normal?
YES: Go to Step 4
NO: Replace the 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-01 terminals 4 and 5. 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-01 and ETACS-ECU connector C-228 for damage.
Q: Are combination meter connector C-01 and ETACS-ECU connector C-228 in good condition?
YES: Go to Step 6
NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the high-beam indicator light illuminates normally.
STEP 6. Check the wiring harness between combination meter connector C-01 and ETACS-ECU connector C-228.
Q: Is the wiring harness between combination meter connector C-01 and ETACS-ECU connector C-228 in good condition?
YES: Repair the ETACS-ECU. Repair the wiring harness. Check that the high-beam indicator light illuminates normally.
NO: Repair the wiring harness. Check that the high-beam indicator light illuminates normally.