Diagnostic Routine C

Diagnostic Routine C

Diagnostic Overview

One Or Both High Beams Are Inoperative

Refer to Wiring Diagram Set 85 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to High Beams .

REFER to Headlamp Assembly .

DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect the BCM (Body Control Module) fuse 39 (15A).

- Inspect the headlamp assembly for damage.

Pinpoint Test

1. CHECK THE LOW BEAM OPERATION

1. Ignition OFF.

2. Place the headlamp switch in the headlamps on position.

Do the low beams illuminate?








2. CHECK THE MULTIFUNCTION SWITCH INPUT

1. Ignition ON.

2. Using a scan tool, view SCCM (Steering Column Control Module) PIDs (Parameter Identifications).

3. Using a scan tool, monitor the SCCM (Steering Column Control Module) FLASH-to-PASS and HEADLAMP_SW PIDs (Parameter Identifications) while placing the multifunction switch in the flash-to-pass and high beam positions.

Do the PID (Parameter Identification) values agree with the multifunction switch position?








3. CHECK FOR VOLTAGE TO THE HEADLAMP

1. Place the headlamp switch in the off position.

2. Disconnect: Inoperative Headlamp.

3. Place the headlamp switch in the headlamps on position and the multifunction switch in the high beam position.

4. Measure:





Is the voltage greater than 11 volts?








4. CHECK THE HEADLAMP GROUND CIRCUIT FOR AN OPEN

1. Measure:





Is the voltage greater than 11 volts?








5. REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP

1. Place the headlamp switch in the off position.

2. Ignition ON.

3. Using a scan tool, clear the DTCs (Diagnostic Trouble Codes) and perform the BCM (Body Control Module) self-test.

4. Place the headlamp switch in the headlamps on position and the multifunction switch in the high beam position.

5. Measure:





Is the voltage greater than 11 volts?








6. CHECK THE BCM (Body Control Module) HIGH BEAM VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280E.

3. Measure:





Is the resistance greater than 10,000 ohms?








7. CHECK THE BCM (Body Control Module) HIGH BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

1. Measure:





Is the resistance less than 3 ohms?








8. 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?