The turn signal lights do not work. However, the other lights do: Hazard, Low & High Beam Headlights, Brake, and Backup.

[burrsj2002]

The turn signal lights do not work. However, the head lights and hazard lights do work. We took the following actions:

1. Fuses.
• Checked under hood fuses. Found no blown fuses. Checked the terminals and found voltage across the tongs.
• Checked fuses inside cabin. Found no blown fuses. In addition, changed the fuse controlling lights anyway.

2. Signal Flasher.
• Changed signal flasher relay, twice. One part from AutoZone and one part from O’Reilly.
• Checked tongs for the relay and found voltage across the tongs.
• Note: The hazard flashers work on the four lights, two front and two rear.

3. Combination Switch (Headlights and Turn Signal).
• Tested switch: headlights, low and high beams, work. Turn signal does not work but hazard lights do not work.
• Change the combination switch.

4. Hazard Switch.
• Tested the flasher and found all signal lights work.
• Changed the switch anyway.

 

[Pete Deering]

The turn signal lights do not work. However, the head lights and hazard lights do work. We took the following actions:

1. Fuses.
• Checked under hood fuses. Found no blown fuses. Checked the terminals and found voltage across the tongs.
• Checked fuses inside cabin. Found no blown fuses. In addition, changed the fuse controlling lights anyway.

2. Signal Flasher.
• Changed signal flasher relay, twice. One part from AutoZone and one part from O’Reilly.
• Checked tongs for the relay and found voltage across the tongs.
• Note: The hazard flashers work on the four lights, two front and two rear.

3. Combination Switch (Headlights and Turn Signal).
• Tested switch: headlights, low and high beams, work. Turn signal does not work but hazard lights do not work.
• Change the combination switch.

4. Hazard Switch.
• Tested the flasher and found all signal lights work.
• Changed the switch anyway.

Did you check the turn signal flasher?

 

[Pete Deering]

Turn Signals

The SCCM (Steering Column Control Module) monitors the multifunction switch position. When the multifunction switch is in the left or right TURN position, the SCCM (Steering Column Control Module) sends a turn signal switch_status message over the communication network to the BCM (Body Control Module) indicating a request for the left or right turn signal.

When the BCM (Body Control Module) receives a request for a turn signal, the BCM (Body Control Module) supplies on/off voltage to the appropriate turn lamps.

The timed on/off cycle for turn lamps is determined by the BCM (Body Control Module) and is set to flash approximately 80 times per minute if both the front and rear turn signal lamps operate correctly. If an individual turn signal lamp is inoperative, the BCM (Body Control Module) fast flashes the remaining turn lamp approximately 160 times per minute to indicate a bulb outage to the driver.

The multifunction switch is a momentary contact switch, with 2 detents for the left turn position and 2 detents for the right turn position. When placed in the first detent and released, the corresponding turn signals flash 3 times and turn off. When the multifunction switch is moved to the second detent and released, the turn signal flashes until the steering wheel is turned in the opposite direction (based on input from the steering wheel rotation sensor), the multifunction switch is moved to the second detent a second time or the vehicle travels farther than 3.22 km (2 mi). The BCM (Body Control Module) monitors the steering wheel rotation sensor and the multifunction switch input to determine when to cancel the turn signals. The BCM (Body Control Module) monitors the distance traveled to determine if the turn signal should be turned off.

The BCM (Body Control Module) also provides an overload protection of the turn lamp output circuits. When an excessive current draw is detected, the BCM (Body Control Module) disables the affected turn lamp circuit driver. REFER to Multifunction Electronic Modules.

 

[burrsj2002]

Turn Signals

The SCCM (Steering Column Control Module) monitors the multifunction switch position. When the multifunction switch is in the left or right TURN position, the SCCM (Steering Column Control Module) sends a turn signal switch_status message over the communication network to the BCM (Body Control Module) indicating a request for the left or right turn signal.

When the BCM (Body Control Module) receives a request for a turn signal, the BCM (Body Control Module) supplies on/off voltage to the appropriate turn lamps.

The timed on/off cycle for turn lamps is determined by the BCM (Body Control Module) and is set to flash approximately 80 times per minute if both the front and rear turn signal lamps operate correctly. If an individual turn signal lamp is inoperative, the BCM (Body Control Module) fast flashes the remaining turn lamp approximately 160 times per minute to indicate a bulb outage to the driver.

The multifunction switch is a momentary contact switch, with 2 detents for the left turn position and 2 detents for the right turn position. When placed in the first detent and released, the corresponding turn signals flash 3 times and turn off. When the multifunction switch is moved to the second detent and released, the turn signal flashes until the steering wheel is turned in the opposite direction (based on input from the steering wheel rotation sensor), the multifunction switch is moved to the second detent a second time or the vehicle travels farther than 3.22 km (2 mi). The BCM (Body Control Module) monitors the steering wheel rotation sensor and the multifunction switch input to determine when to cancel the turn signals. The BCM (Body Control Module) monitors the distance traveled to determine if the turn signal should be turned off.

The BCM (Body Control Module) also provides an overload protection of the turn lamp output circuits. When an excessive current draw is detected, the BCM (Body Control Module) disables the affected turn lamp circuit driver. REFER to Multifunction Electronic Modules.

Thank you. I will check this potential fault.