Circuit Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The BCM monitors the LF turn signal circuit in order to determine the status of the turn signal switch. If the BCM detects an oscillating voltage on the LH turn signal monitor circuit, the BCM interprets this as a LF turn signal ON request from the turn signal switch. The BCM will de-energize the LH DRL relay, which will disable the LF turn signal lamp (which is ON for the DRL), this allows the LF turn signal to flash. If the BCM does not detect an oscillating voltage on the LH turn signal monitor circuit, the BCM interprets this as the LF turn signal being OFF. The BCM will then energize the LH DRL relay and continue normal DRL operation. The BCM monitors the LF turn signal monitor circuit and determines how long voltage is applied. If the voltage is applied for longer than expected, a malfunction is present and a DTC will set.