B2603
CIRCUIT DESCRIPTIONThe body control module (BCM) controls the DRL relay by grounding the control circuit of the DRL relay coil.
CONDITIONS FOR RUNNING THE DTC
^ Voltage supplied to the module is in the normal operating voltage range (approximately 10 - 16 volts).
^ The DRL feature must be enabled.
^ The DRLs must be commanded ON.
CONDITIONS FOR SETTING THE DTC
^ The BCM detects a short to battery positive voltage in the control circuit of the DRL relay coil when the DRLs are ON.
^ The condition above must be present for more than 3 ms.
ACTION TAKEN WHEN THE DTC SETS
^ The BCM stores DTC B2603 in memory.
^ The SERVICE VEHICLE SOON telltale illuminates.
CONDITIONS FOR CLEARING THE DTC
^ A current DTC B2603 clears if the BCM no longer detects a short to battery positive voltage in the control circuit of the DRL relay coil.
^ A history DTC B2603 clears after 100 consecutive ignition cycles.
^ The BCM receives the Clear Code commend from the scan tool.
DIAGNOSTIC AIDS
^ If the DTC B2603 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.
^ An intermittent short to voltage in the following locations may cause an intermittent malfunction to occur:
- The control circuit of the DRL relay coil
- The DRL relay
- The BCM
TEST
