Turn Signal Lamp Circuit

TURN SIGNAL LAMP CIRCUIT

Description

The BCM monitors inputs from the combination 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

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

LH: Turn signal lamp LH blinking
RH: Turn signal lamp RH blinking
OFF: The turn signal lamp OFF

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


Diagnosis Procedure

Regarding Wiring Diagram information, Turn Signal And Hazard Warning Lamps Coupe (coupe) or Turn Signal And Hazard Warning Lamps Sedan (sedan).

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, the door mirror connector (if equipped with turn signal in mirrors) and the rear combination lamp connector.
3.Turn the ignition switch ON.
4.With operating the turn signal switch, check the voltage between the front combination lamp harness connector and the ground.









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





6.With operating the turn signal switch, check the voltage between the door mirror (if equipped with turn signal in the mirrors) harness connector and the ground.





Is the measurement value normal?
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 M17.
3.Check the continuity between the BCM harness connector and the front combination lamp, the rear combination lamp harness connector and the door mirror connector (if equipped with turn signal in mirrors).





Does continuity exist?
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 the ground.





Does continuity exist?
YES- Repair the harnesses or connectors.
NO- Replace BCM. Service and Repair.

5. CHECK TURN SIGNAL LAMP GROUND CIRCUIT

1.Turn the ignition switch OFF.
2.Check continuity between the front combination lamp, the rear combination lamp and the door mirror (if equipped with turn signals in mirrors) and ground.





Does continuity exist?
YES- Replace the front combination lamp, the rear combination lamp or the door mirror (if equipped with turn signal in mirrors).
NO- Repair the harnesses or connectors.