Diagnostic Routine I

Diagnostic Routine I

Diagnostic Overview

The Body Control Module (BCM) Does Not Respond To The Scan Tool

Refer to Wiring Diagram Set 11 for schematic and connector information Electrical Diagrams.

Refer to Wiring Diagram Set 13 for schematic and connector information Electrical Diagrams.

Refer to Wiring Diagram Set 14 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The BCM (Body Control Module) module communicates with the scan tool through the HS-CAN (High Speed Controller Area Network) and communicates with the other modules through the MS-CAN (Medium Speed Controller Area Network).

Visual Inspection and Diagnostic Pre-checks

Verify BCM (Body Control Module) fuse 18 (10A) is OK.

Pinpoint Test

1. CHECK POWER ON BOTH SIDES OF THE BCM (Body Control Module) POWER FUSE

1. Ignition ON.

2. Measure:





Is the voltage greater than 11 volts on both sides of the fuse?






2. CHECK THE BCM (Body Control Module) GROUND CIRCUIT FOR AN OPEN

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

2. Measure:





Is the resistance less than 3 ohms?






3. CHECK THE HS-CAN (High Speed Controller Area Network) TERMINATION RESISTANCE

1. Ignition OFF.

2. Disconnect: Negative Battery Cable.

3. Disconnect the scan tool cable from the DLC (Data Link Connector).

4. Measure:





Is the resistance between 54 and 66 ohms?






4. CHECK THE MS-CAN (Medium Speed Controller Area Network) TERMINATION RESISTANCE

1. Measure:





Is the resistance between 54 and 66 ohms?






5. CHECK THE MS-CAN (Medium Speed Controller Area Network) TERMINATION RESISTANCE WITH THE HVAC (Heating, Ventilation, and Air Conditioning) MODULE DISCONNECTED

1. Disconnect: HVAC (Heating, Ventilation, and Air Conditioning) module C228A.

2. Measure:





Is the resistance between 108 and 132 ohms?






6. CHECK THE MS-CAN (Medium Speed Controller Area Network) CIRCUITS BETWEEN THE BCM (Body Control Module) AND THE DLC (Data Link Connector) FOR AN OPEN

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

2. Measure:





Are the resistances less than 3 ohms?






7. CHECK THE MS-CAN (Medium Speed Controller Area Network) CIRCUITS FOR A SHORT TO POWER

1. Connect: BCM (Body Control Module) C2280B.

2. Ignition ON.

3. Measure:





Is the voltage greater than 3 volts on either circuit?






8. CHECK THE MS-CAN (Medium Speed Controller Area Network) CIRCUITS FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: Negative Battery Cable.

3. Measure:





Are the resistances greater than 10,000 ohms?






9. CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS BETWEEN THE BCM (Body Control Module) AND THE DLC (Data Link Connector) FOR AN OPEN

1. Disconnect: BCM (Body Control Module) C2280F.

2. Measure:





Are the resistances less than 3 ohms?






10. CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS FOR A SHORT TO POWER

1. Connect: BCM (Body Control Module) C2280F.

2. Ignition ON.

3. Measure:





Is the voltage greater than 3 volts on either circuit?






11. CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS FOR A SHORT TO GROUND

1. Disconnect: Negative Battery Cable.

2. Measure:





Are the resistances greater than 10,000 ohms?






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

1. Ignition OFF.

2. Disconnect and inspect the BCM (Body Control Module) connector.

3. Repair:

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

4. Reconnect the BCM (Body Control Module) connector. Make sure it seats and latches correctly.

5. Operate the system and verify the concern is still present.

Is the concern still present?