Turn Signal Lamps

Battery voltage supplied to the body control module (BCM) from the fuses listed below is used for turn signal and hazard lamp operation.

• LT TRN/SIG fuse for the left turn signals
• CTSY/RF TRN fuse for the right front turn signal
• RR TRN/SIG fuse for the right rear turn signal

When the turn signal switch is place in either the LEFT or RIGHT position, ground from G300 is applied through the turn signal switch signal circuit to the BCM indicating the turn signal request. In response to this signal, the BCM applies a pulsating voltage to the front and rear turn signal lamps supply voltage circuits cycling the lamps ON and OFF. At the same time the BCM sends a GMLAN serial data message to the instrument panel cluster (IPC) to cycle the appropriate turn signal indicator ON and OFF.

Ground for the turn signal lamps is supplied as follows:

• G104 provides ground for the left and right front turn signal lamps
• G402 provides ground for the left rear stop/tail/turn signal lamps
• G403 provides ground for the right rear stop/tail/turn signal lamps
• The driver door module (DDM) provides a low reference for the left outside rearview mirror turn signal
• The front passenger door module (FPDM) provides a low reference for the right outside rearview mirror turn signal