| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
B+, BCM C4 Terminal 2  | B2615 00  | B2615 00  | --  | --  | 
Courtesy Lamps Supply Voltage  | B2615 00  | 2  | 1  | --  | 
Right Front Turn Signal Lamp Supply Voltage  | B2615 00  | 3  | 4  | --  | 
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Battery voltage for the courtesy lamps is supplied at all times, from the CTSY/RF TRN Fuse located in the rear fuse block, to the body control module (BCM). When the BCM receives a signal to command the courtesy lamps ON, it then applies voltage through the courtesy lamps supply voltage circuits to the courtesy lamps listed below.
| • | Courtesy Lamp Module | 
| • | Left and right roof rail courtesy/reading lamps | 
| • | Left and right rear door courtesy/puddle lamps | 
| • | Overhead console lamp | 
| • | The BCM attempts to illuminate the courtesy lamps. | 
| • | Engine ON, the BCM attempts to illuminate the day time running lamps. | 
| • | Ignition ON with the right turn signal switch active, the BCM attempts to illuminate the right front turn signal. | 
| • | The BCM detects a short to ground on the courtesy lamp supply voltage circuit. | 
| • | The BCM detects a short to ground on the right front turn signal supply voltage circuit. | 
The BCM will not attempt to activate courtesy lamps or the right front turn signal.
| • | The condition responsible for setting the DTC no longer exists. | 
| • | A history DTC will clear once 100 consecutive malfunction ignition cycles have occurred. | 
Lighting Systems Connector End Views
Ignition ON, command the Courtesy Lamps ON and OFF with a scan tool. The courtesy lamps should turn ON and OFF when changing between commanded states.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the supply voltage circuits listed below for a short to ground. | 
| • | Right front turn signal lamp supply voltage terminal 5 C4 | 
| • | Courtesy lamp supply voltage terminal 1 C6 | 
| • | Courtesy lamp supply voltage terminal 5 C2 | 
| • | Right front turn signal lamp supply voltage terminal 5 C4 | 
| • | Courtesy lamp supply voltage terminal 1 C6 | 
| • | Courtesy lamp supply voltage terminal 5 C2 | 
| ⇒ | If the DTC resets, test the supply voltage circuits for a short to ground. If the circuits test normal, replace the BCM. | 
| ⇒ | If the DTC resets, test or replace the component responsible for setting the DTC. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |