• | 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 |
---|---|---|---|---|
I/P Dimmer Voltage Reference | B1395 03 and B3600 03 | B1395 03, B2652 00, and B3600 03 | B1395 07 | -- |
Stop Lamp Switch Signal | B1395 03 and B3600 03 | 3 | 3 | -- |
CHMSL Control | B3884 00 | 3 | 3 | -- |
Stop Lamp Control | B3445 00 | 3 | 3 | -- |
I/P Dimmer Switch Low Reference | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 2 | -- | -- |
1. Dimmer Switch Malfunction 2. Interior Backlighting Malfunction 3. Stop Lamp Switch Malfunction |
When the brake pedal is applied, the brake pedal switch normally closed contact signal circuit voltage is interrupted to the body control module (BCM). The BCM then applies a voltage to the stop lamp supply voltage circuit to the stop lamps.
• | The ignition is ON. |
• | The stop lamps must be commanded ON. |
The BCM detects a short to ground in the stop lamp supply voltage circuit when the stop lamps are commanded ON.
The stop lamps do not illuminate.
• | The conditions for setting the DTC are no longer present. |
• | A history DTC clears after 100 malfunction-free ignition cycles. |
• | The BCM receives the clear code command from the scan tool. |
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
• | Turn Signal Lamp terminal A |
• | Tail/Stop Lamp terminal C |
• | Center High Mounted Stop Lamp terminal A |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If all circuits test normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |