Inspection Procedure 5
Inspection Procedure 5: Any Of The Headlights Does Not Illuminate.CAUTION: If the discharge type headlights do not illuminate, fully understand the precautions in "Service precautions for discharge headlight" before proceeding with the troubleshooting. Refer to Symptom Chart - Checking Order
Headlights Circuit <Halogen Type>:
Headlight Circuit <Discharge Type> (Part 1):
Headlight Circuit <Discharge Type> (Part 2):
TECHNICAL DESCRIPTION (COMMENT)
When any of the headlights does not illuminate, the wiring harness, connector(s), or the bulb may have a problem, or the fuse may be burned out.
TROUBLESHOOTING HINTS
- Malfunction of the headlight bulbs
- Malfunction of the headlight assembly
- Damaged harness wires and connectors
DIAGNOSIS
Required Special Tools:
- MB992006: Extra fine probe
- MB991223: Harness set
STEP 1. Check headlight (LOW) connector A-37
Q: Is headlight (LOW) assembly connector A-37
YES : Go to Step 2.
NO : Repair the defective connector.
STEP 2. Check bulb.
Check the bulb(s) of headlight that does not illuminate.
NOTE: If discharge-type lower beam headlights do not illuminate, their bulbs cannot be inspected. In this case, assume the bulbs to be normal and proceed with steps.
Q: Is the bulb in good condition?
YES : Go to Step 3.
NO : Replace the bulb(s) of the light that does not illuminate.
STEP 3. Check the ground circuit to the headlight assembly (LOW) or headlight assembly (HIGH). Measure the resistance at headlight assembly (LOW) connector A-37
1. Disconnect the connector, and measure at the wiring harness side.
2. Resistance between the connector of light which does not illuminate and ground.
- Resistance between the A-37 (LH), A-56 (RH) headlight assembly connector terminal 8 and ground.
- Resistance between the A-37 (LH), A-56 (RH) headlight assembly connector terminal 9 and ground.
- Resistance between the A-38 (LH), A-55 (RH) headlight assembly connector terminal 2 and ground.
OK: The resistance should be 2 ohms or less.
Q: Is the measured resistance 2 ohms or less?
YES : Go to Step 5.
NO : Go to Step 4.
STEP 4. Check the wiring harness between headlight assembly (LOW) connector A-37
- Check the ground wires for open circuit.
Q: Is the wiring harness between headlight assembly (LOW) connector A-37
YES : The trouble can be an intermittent malfunction (Refer to general (body and chassis) - How to Cope with Intermittent Malfunction).
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. Verify that the headlights illuminate normally.
STEP 5. Check the wiring harness between headlight assembly (LOW) connector A-37
- Check the power supply line for open circuit.
Q: Is the wiring harness between headlight assembly (LOW) connector A-37
YES : Replace the headlight assembly that does not illuminate.
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. Verify that the headlights illuminate normally.