Test Description

The numbers below refer to the step numbers on the diagnostic table. See Fig 1 and Fig 2 .

1. 2
   
   Listen for an audible click when the courtesy lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
2. 3
   
   Tests for voltage at the coil side of the courtesy lamp relay. The CTSY fuse supplies power to the coil side of the courtesy lamp relay.
3. 4
   
   Verifies that the body control module is providing ground to the courtesy lamp relay.
4. 5
   
   Tests if ground is constantly being applied to the courtesy lamp relay.
5. 12
   
   After replacement of the BCM, you must calibrate the new module for proper operation.

Fig 1: DTC B2617 Diagnostic Table (Steps 1-3)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B2617 Diagnostic Table (Steps 4-13)

Courtesy of GENERAL MOTORS CORP.