Turn Signal?

Turn Signal Circuit:

DESCRIPTION:

The turn signal flasher is provided voltage through the turn signal fuse (15) whenever the ignition is "ON." When the turn signal switch closes, providing a path to ground through the left or right turn signal lamps, the flasher alternately opens and closes. The BCM monitors circuit 16 to determine if the turn signal switch is closed and the turn signal lamps are "ON." If the turn signals are left on for more than a quarter mile, the BCM will send the "TURN SIGNAL ON" message to the driver information center.

The voltage seen at the BCM can be monitored through parameter BI17 in diagnostic mode. The correct input state should be:

Signals "OFF" - Input HI.

Either signal "ON" - Input alternates between "HI" and "LO." Bulbs lit while "HI."

TEST CONDITIONS:

Turn signal "ON."

FAILURE CONDITIONS:

Turn signal has been "ON" for over 1/4 of a mile.

ACTION TAKEN:

Display "TURN SIGNAL ON" message.

DIAGNOSIS:

Erroneous message - Intermittent short to ground on circuit 16.

No message - Open in circuit 16.