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. Diagrams By Number

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

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

PINPOINT TEST J: THE BCM 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. Refer to Battery, Mounting and Cables Battery Disconnect.

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J1 CHECK THE BCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: BCM C2280B.
- Ignition ON.
- Measure the voltage between the BCM 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. CLEAR the DTCs. REPEAT the network test with the scan tool. Diagrams By Number

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J2 CHECK THE BCM GROUND CIRCUITS FOR AN OPEN

- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the BCM C2280B-7, circuit GD115 (BK/GY), harness side and ground; and C2280B-16, circuit GD115 (BK/GY), harness side and ground.




- Disconnect: BCM C2280A.
- Measure the resistance between the BCM C2280A-12, circuit GD133 (BK), harness side and ground; and C2280A-16, circuit GD115 (BK/BU), 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.

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J3 CHECK THE MS-CAN CIRCUITS BETWEEN THE BCM AND THE DLC FOR AN OPEN

- Disconnect: BCM C2280F.
- Measure the resistance between the BCM C2280F-24, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.




- Measure the resistance between the BCM C2280F-23, circuit VDB07 (VT/OG), harness side and the DLC 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.

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J4 CHECK FOR CORRECT BCM OPERATION

- Disconnect the BCM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the BCM 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. REFER to Multifunction Electronic Modules Body Control Module (BCM). 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.

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