Some 2024 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD trucks may have an electrical condition where the headlamps flash and/or the windshield wipers pause while wiping. DTC P0606 (Control Module Processor Performance) may be set in the Lighting Control Module. (Fig. 3) The headlamp and/or wipers condition may be caused by a low battery state of charge, which can cause voltage diagnostics to fail in the Lighting Control Module.
Fig. 3
The Body Control Module (BCM) communicates with the Lighting Control Module over CAN to request headlamp illumination and wiper operation.
If the vehicle’s battery goes below the threshold in the Lighting Control Module during a cranking event or the battery is discharged and needs a jump start, the Lighting Control Module may go into a reset every 8-10 seconds, causing the headlamps to flash.
If the headlamps are flashing, do not replace the Lighting Control Module. (Fig. 4) Test the battery following the recommended testing procedures in the appropriate Service Information and replace the battery if necessary.
To correct the flashing headlamps and clear DTC P0606, disconnect the battery, which will reset the Lighting Control Module.
Fig. 4
For additional information, refer to Bulletin #24-NA-005.
– Thanks to Kevin Minor
