B3840 (Park Lamp Signal Circuit Low) and/or B3841 (Park Lamp Signal Circuit High) - keywords body control park lamp signal

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

During a diagnostic probe the dealer may find a history B3840 (Park Lamp Signal Circuit Low) and/or B3841 (Park Lamp Signal Circuit High) DTC in the system that may or may not return if cleared. The vehicle will have no MIL's and/or warning indicators displayed on the IPC or DIC. Service Information diagnostic charts, ID # 1466430 and ID # 1466432, both lead to a BCM replacement if these codes are present. These codes are usually set due to a timing mismatch when the unlock button on the key fobs are pressed several times, or when the headlamp switch is toggled back and forth repeatedly.

This is a normal condition and the BCM should NOT be replaced. Consult with the customer and request the repeated door unlock from the key fob and/or headlamp switch toggling be stopped as it is likely inducing the condition.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.