Turn Signal Lamp: Testing and Inspection

Turn Signal Lamp Circuit Check

Description

The BCM monitors inputs from the combination switch (lighting and turn signal switch) to determine when to activate the turn signals. The BCM outputs voltage direction to the left and right turn signals during turn signal operation or both during hazard warning operation. The BCM sends a turn signal indicator request to the combination meter via the CAN communication lines.

The BCM performs the fast flasher operation (fail-safe) if any bulb or harness of the turn signal lamp circuit is open.

NOTE:

Turn signal lamp blinks at normal speed when using the hazard warning lamp.

Component Function Check

1. CHECK TURN SIGNAL LAMP

WITH SDT
1 Select "FLASHER" of BCM (FLASHER) active test item.
2 With operating the test items, check that the turn signal lamp blinks.






Does the turn signal lamp blink?
YES
Turn signal lamp circuit is normal.
NO
Refer to "Diagnosis Procedure".

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Turn Signal and Hazard Warning Lamp System: Wiring Diagram] [1][2]Electrical Diagrams.

1. CHECK TURN SIGNAL LAMP BULB

Check the applicable lamp bulb to be sure the proper bulb standard is in use and the bulb is not open.

Is the bulb OK?
YES
GO TO 2
NO
Replace the bulb.

2. CHECK TURN SIGNAL LAMP OUTPUT VOLTAGE

1 Turn the ignition switch OFF.
2 Disconnect the front combination lamp connector and the rear combination lamp connector.
3 Turn the ignition switch ON.
4 With turn signal switch operating, check the voltage between the front combination lamp harness connector and ground.






5 With turn signal switch operating, check the voltage between the rear combination lamp harness connector and ground.






Is voltage reading as specified?
YES
GO TO 5
NO
GO TO 3

3. CHECK TURN SIGNAL LAMP CIRCUIT FOR OPEN

1 Turn the ignition switch OFF.
2 Disconnect BCM connector M20.
3 Check continuity between the BCM harness connector and the front combination lamps harness connector.






4 Check continuity between the BCM harness connector and the rear combination lamp harness connector.






Are continuity results as specified?
YES
GO TO 4
NO
Repair the harnesses or connectors.

4. CHECK TURN SIGNAL LAMP SHORT CIRCUIT

Check continuity between the BCM harness connector and ground.











Does continuity exist?
YES
Repair the harnesses or connectors.
NO
Replace BCM. Refer to [BCM: Removal and Installation] Removal and Replacement.

5. CHECK TURN SIGNAL LAMP GROUND CIRCUIT

1 Check continuity between the front combination lamp harness connector and ground.






2 Check continuity between the rear combination lamp harness connector and ground.






Are continuity results as specified?
YES
Replace the malfunctioning lamp.
NO
Repair the harnesses or connectors.