Diagnostic Routine AB
Diagnostic Routine AB
Diagnostic Overview
All the Reversing Lamps Are Inoperative
Refer to Wiring Diagram Set 93 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
REFER to Reversing Lamps - Automatic Transmission .
REFER to Reversing Lamps - Manual Transmission .
Visual Inspection and Diagnostic Pre-checks
- Inspect the bulbs and make sure they are OK.
- Inspect the BCM (Body Control Module) fuse 76 (10A).
Pinpoint Test
1. CHECK THE PCM (Powertrain Control Module) REVERSE GEAR PID
1. Apply the parking brake.
2. Ignition ON.
3. Using a scan tool, view TCM (Transmission Control Module) (automatic transmission) or PCM (Powertrain Control Module) (manual transmission) PIDs (Parameter Identifications).
4. For vehicles equipped with an automatic transmission, monitor the TCM (Transmission Control Module) GEAR_ENGAGED PID (Parameter Identification).
5. For vehicles equipped with a manual transmission, monitor the PCM (Powertrain Control Module) REV_SW PID (Parameter Identification).
6. Place the transmission in the reverse gear.
Does the PID (Parameter Identification) indicate the transmission is in reverse gear?
2. BYPASS THE REVERSING LAMP SWITCH
1. Ignition OFF.
2. Disconnect: Reversing Lamp Switch.
3. Connect a fused jumper wire:
4. Ignition ON.
5. Using a scan tool, monitor the PCM (Powertrain Control Module) REV_SW PID (Parameter Identification).
Does the PID (Parameter Identification) indicate the transmission is in reverse gear?
3. CHECK THE REVERSING LAMP SWITCH GROUND CIRCUIT FOR AN OPEN
1. Connect a fused jumper wire:
2. Using a scan tool, monitor the PCM (Powertrain Control Module) REV_SW PID (Parameter Identification).
Does the PID (Parameter Identification) indicate the transmission is in reverse gear?
4. CHECK THE REVERSING LAMP SWITCH INPUT CIRCUIT FOR AN OPEN
1. Ignition OFF.
2. Disconnect: PCM (Powertrain Control Module) C175B.
3. Measure:
Is the resistance less than 3 ohms?
5. CHECK THE REVERSING LAMPS GROUND CIRCUIT FOR AN OPEN
1. Ignition OFF.
2. Disconnect: Left Reverse Lamp.
3. Ignition ON.
4. Place the transmission in the reverse gear.
5. Measure:
Is the voltage greater than 11 volts?
6. 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?
7. 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?
