Pinpoint Test I: The Driver Seat Module (DSM) Does Not Communicate With the Scan Tool

Communications Network

Pinpoint Test I: The Driver Seat Module (DSM) Does Not Communicate With the Scan Tool


Normal Operation

The Driver Seat Module (DSM) is optional equipment. The DSM (Driver Seat Module) 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

- DSM (Driver Seat Module)

PINPOINT TEST I : THE DSM (Driver Seat 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.

I1 CHECK THE DSM (Driver Seat Module) VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: DSM (Driver Seat Module) C341A and DSM (Driver Seat Module) C341B.

- Measure the voltage between the DSM (Driver Seat Module) C341A-1, circuit CBX05 (VT/RD), harness side and ground.





- Measure the voltage between the DSM (Driver Seat Module) C341B-1, circuit CBX03 (BU/RD), harness side and ground.





Are the voltages greater than 10 volts?

Yes
GO to I2.

No
VERIFY the Battery Junction Box (BJB) fuse 9 (30A) or the Body Control Module (BCM) fuse 6 (5A) is OK. If OK, REPAIR the circuit in question. 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. [1][2]Diagrams By Number

I2 CHECK THE DSM (Driver Seat Module) GROUND CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the DSM (Driver Seat Module) C341A-2, circuit GD906 (BK/GY), harness side and ground.





- Measure the resistance between the DSM (Driver Seat Module) C341B-24, circuit GD905 (BK/GN), harness side and ground.





Are the resistances less than 5 ohms?

Yes
GO to I3.

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

I3 CHECK THE MS-CAN (Medium Speed Controller Area Network) CIRCUITS BETWEEN THE DSM (Driver Seat Module) AND THE DLC (Data Link Connector) FOR AN OPEN

- Ignition OFF.

- Disconnect: DSM (Driver Seat Module) C341D.

- Measure the resistance between the DSM (Driver Seat Module) C341D-10, 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 DSM (Driver Seat Module) C341D-9, 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 I4.

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

I4 CHECK FOR CORRECT DSM (Driver Seat Module) OPERATION

- Disconnect all the DSM (Driver Seat Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the DSM (Driver Seat Module) connectors and make sure they seat correctly.

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

Is the concern still present?

Yes
INSTALL a new DSM (Driver Seat Module). CLEAR the DTCs. REPEAT the network test with the scan tool. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.