GM Service Manual Online
For 1990-2009 cars only

Turn Signal Flashes Fast - keywords bulb flasher lamp light switch wire

Subject:Turn Signal Flashes Fast

Models:2007 Chevrolet Silverado
2007 GMC Sierra



This PI is being updated to add fix information. Please discard PIT4181A.


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

Some customers may comment that their turn signals (left, right or both) are flashing at a high rate of speed. Root cause appears to be a software anomaly in the BCM.

Recommendation/Instructions:

Reprogram the Body Control Module (BCM) with updated software. This new service software was released to TIS2Web data update version 12.0 available December 4, 2006. As always make sure your Tech 2 is updated with the latest software version.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.