Diagnostic Routine B

Diagnostic Routine B

Diagnostic Overview

One Or Both Low Beams Are Inoperative

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

Normal Operation and Fault Conditions

REFER to Low Beams .

BCM (Body Control Module) DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect the bulbs and make sure they are OK.

- Inspect the headlamp assembly for damage.

Pinpoint Test

1. DETERMINE IF ONE OR BOTH LOW BEAMS ARE INOPERATIVE

1. Ignition ON.

2. Place the headlamp switch in the HEADLAMPS ON position.

Are both low beams inoperative?







2. CHECK FOR VOLTAGE TO THE HEADLAMP

1. Ignition OFF.

2. Place the headlamp switch in the OFF position.

3. Disconnect: Inoperative Headlamp.

4. Ignition ON.

5. Place the headlamp switch in the HEADLAMPS ON position.

6. Measure:





Is the voltage greater than 11 volts?







3. CHECK THE HEADLAMP GROUND CIRCUIT FOR AN OPEN

1. Measure:





Is the voltage greater than 11 volts?







4. CHECK THE LOW BEAM SUPPLY CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Place the headlamp switch in the OFF position.

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

4. Measure:





Is the resistance greater than 10,000 ohms?







5. CHECK THE LOW BEAM SUPPLY CIRCUIT FOR AN OPEN

1. Measure:





Is the resistance less than 3 ohms?







6. 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?