Inspection Procedure 13: One of the turn-signal lamps does not illuminate.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.

COMMENTS ON TROUBLE SYMPTOM
If one of the turn-signal lamps does not illuminate, the wiring harness connector(s) or the bulb may be defective.

PROBABLE CAUSES

  • Defective turn-signal lamp bulb
  • Malfunction of side turn-signal lamp assembly <Fender panel type>
  • Malfunction of side turn-signal lamp assembly <Door mirror type>
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Confirm which turn-signal lamp is defective.

Q. Which turn-signal lamp fails to illuminate correctly?
YES (All of the turn-signal lamps illuminate normally) : The procedure is complete.
NO (Only the front or rear turn-signal lamps does not illuminate normally) : Refer to ETACS diagnosis code chart.
NO (Only the side turn-signal lamps does not illuminate normally) : Go to Step 2.

STEP 2. Resistance measurement at the side turn-signal lamp connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Measure the resistance between the defective lamp connector terminal and body earth.

  • Measure the resistance between the side turn-signal lamp (LH) connector (earth terminal) and the body earth <Fender panel type>.
  • Measure the resistance between the side turn-signal lamp (RH) connector (earth terminal) and the body earth <Fender panel type>.
  • Measure the resistance between the door mirror assembly (LH) connector (earth terminal) and the body earth <Door mirror type>.
  • Measure the resistance between the door mirror assembly (RH) connector (earth terminal) and the body earth <Door mirror type>.
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Go to Step 4.
Go to Step 3.

STEP 3. Check of open circuit in earth line between side turn-signal lamp connector <Fender mirror type>, door mirror assembly <Door mirror type> and body earth.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.

STEP 4. Check of open circuit in TURN LH or TURN RH line between side turn-signal lamp connector <Fender mirror type>, door mirror assembly connector <Door mirror type> and ETACS-ECU connector.

Q. Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.

STEP 5. Retest the system.
Check that the side turn-signal lamp flashes normally when the turn-signal switch is operated.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the side turn-signal lamp assembly <Fender panel type>, side turn-signal lamp assembly (Refer to GROUP 51 - Door Mirror ) <Door mirror type>.