Pinpoint Test J: The Body Control Module (BCM) Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test J: The Body Control Module (BCM) Does Not Respond To The Scan Tool

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

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information Electrical Diagrams.

Normal Operation

The Body Control Module (BCM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- BCM (Body Control Module)

PINPOINT TEST J : THE BCM (Body Control Module) DOES NOT RESPOND TO THE SCAN TOOL

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

J1 CHECK THE BCM (Body Control Module) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: BCM (Body Control Module) C2280B.

- Ignition ON.

- Measure the voltage between the BCM (Body Control Module) C2280B-4, circuit CBP21 (BU/GY) harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to J2.

No
VERIFY the Central Junction Box (CJB) fuse 21 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams. CLEAR the DTCs. REPEAT the network test with the scan tool.

J2 CHECK THE BCM (Body Control Module) GROUND CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the BCM (Body Control Module) C2280B-7, circuit GD115 (BK/GY), harness side and ground; and C2280B-16, circuit GD115 (BK/GY), harness side and ground.





- Disconnect: BCM (Body Control Module) C2280A.

- Measure the resistance between the BCM (Body Control Module) C2280A-12, circuit GD133 (BK), harness side and ground; and C2280A-16, circuit GD156 (BK/VT), harness side and ground.





Are the resistances less than 5 ohms?

Yes
GO to J3.

No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

J3 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

- Disconnect: BCM (Body Control Module) C2280F.

- Measure the resistance between the BCM (Body Control Module) C2280F-24, circuit VDB06 (GY/OG), harness side and the DLC (Data Link Connector) C251-3, circuit VDB06 (GY/OG), harness side.





- Measure the resistance between the BCM (Body Control Module) C2280F-23, circuit VDB07 (VT/OG), harness side and the DLC (Data Link Connector) C251-11, circuit VDB07 (VT/OG), harness side.





Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to J4.

No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

J4 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect the BCM (Body Control Module) connector.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the BCM (Body Control Module) connector and make sure it seats correctly.

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

Is the concern still present?

Yes
INSTALL a new BCM (Body Control Module). CLEAR the DTCs. REPEAT the network test with the scan tool.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.