GM Service Manual Online
For 1990-2009 cars only

DTC

Diagnostic Procedure

Module(s)

B2556

DTC B2556 Interior Lamp Rheostat Circuit Range

IPM

B2627

DTC B2627 Pass Compartment Dimming #2 Circuit Low

CCP

B2628

DTC B2628 Pass Compartment Dimming #2 Circuit High

CCP

B2641

DTC B2641 Delayed Exterior Lighting Ctrl CKT Range

IPM

B2642

DTC B2642 Delayed Exterior Lighting Ctrl CKT Low

CCP

B2643

DTC B2643 Delayed Exterior Lighting Ctrl CKT High

CCP

B2646

DTC B2646 Ambient Light Sensor Circuit Range

IPM

B2647

DTC B2647 Ambient Light Sensor Circuit Low

CCP

B2648

DTC B2648 Ambient Light Sensor Circuit High

CCP

B2657

DTC B2657 Ignition Halo Lamp Output Circuit Malf

CCP