Diagnostic Routine O

Diagnostic Routine O

Diagnostic Overview

The Stoplamps Are On Continuously

Refer to Wiring Diagram Set 90 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Stoplamps .

REFER to Stoplamp Switch .

BCM (Body Control Module) DTC Fault Trigger Conditions





RFA (Remote Function Actuator) Module DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect the stoplamp switch for damage.

Pinpoint Test

1. CHECK THE STOPLAMP SWITCH

1. Ignition OFF.

2. Disconnect: Stoplamp Switch.

3. Ignition ON.

4. Observe the stoplamps.

Do the stoplamps continue to illuminate?








2. CHECK THE TBC (Trailer Brake Control) MODULE

1. Ignition OFF.

2. Disconnect: TBC (Trailer Brake Control) Module.

3. Ignition ON.

Do the stoplamps continue to illuminate?








3. CHECK THE PCM (Powertrain Control Module)

1. Ignition OFF.

2. Disconnect: PCM (Powertrain Control Module) C175B.

3. Ignition ON.

Do the stoplamps continue to illuminate?








4. CHECK THE RFA (Remote Function Actuator) MODULE

1. Ignition OFF.

2. Disconnect: RFA (Remote Function Actuator) Module C2153C.

3. Ignition ON.

Do the stoplamps continue to illuminate?








5. CHECK THE BCM (Body Control Module) STOPLAMP SWITCH INPUT CIRCUIT FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280B.

3. Ignition ON.

4. Measure:





Is any voltage present?








6. CHECK THE BCM (Body Control Module) TBC (Trailer Brake Control) MODULE OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

1. Measure:





Is any voltage present?








7. CHECK THE BCM (Body Control Module) STOPLAMP OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280D.

3. Ignition ON.

Do the stoplamps continue to illuminate?








8. CHECK FOR CORRECT PCM (Powertrain Control Module) OPERATION

1. Disconnect and inspect all PCM (Powertrain Control Module) connectors.

2. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

3. Reconnect the PCM (Powertrain Control Module) connectors. Make sure they seat and latch correctly.

4. Operate the system and determine if the concern is still present.

Is the concern still present?








9. CHECK FOR CORRECT RFA (Remote Function Actuator) MODULE OPERATION

1. Disconnect and inspect all RFA (Remote Function Actuator) module connectors.

2. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

3. Reconnect the RFA (Remote Function Actuator) module connectors. Make sure they seat and latch correctly.

4. Operate the system and determine if the concern is still present.

Is the concern still present?








10. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Disconnect and inspect all BCM (Body Control Module) connectors.

2. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

3. Reconnect the BCM (Body Control Module) connectors. Make sure they seat and latch correctly.

4. Operate the system and determine if the concern is still present.

Is the concern still present?