Pinpoint Test H: The Driver Seat Module (DSM) Does Not Respond to the Scan Tool

Communications Network


Pinpoint Tests

Pinpoint Test H: The Driver Seat Module (DSM) Does Not Respond To The Scan Tool

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

Refer to Wiring Diagram Set 123, Memory Seats for schematic and connector information. Diagrams By Number

Normal Operation

The Driver Seat Module (DSM) communicates with the scan tool through the Standard Corporate Protocol (SCP) communication network. Circuits 914 (TN/OG) (SCP +) and 915 (PK/LB) (SCP-) provide the network connection to the DSM. Voltage for the DSM is provided by circuit 1524 (DB). Circuit 676 (PK/OG) provides ground.

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- DSM



PINPOINT TEST H: THE DSM 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 will result in false resistance readings. Refer to Battery.

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H1 CHECK THE DSM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect the scan tool cable from the Data Link Connector (DLC).
- Disconnect: DSM C341c.
- Ignition ON.
- Measure the voltage between the DSM C341c-14, circuit 1524 (DB), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to H2.

No
VERIFY the Central Junction Box (CJB) fuse 19 (7.5A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the short circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.

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H2 CHECK THE DSM GROUND CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the DSM C341c-1, circuit 676 (PK/OG), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to H3.

No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

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H3 CHECK THE SCP CIRCUITS BETWEEN THE DSM AND THE DLC FOR AN OPEN


- Measure the resistance between the DSM C341c-25, circuit 914 (TN/OG), harness side and the DLC C251-2, circuit 914 (TN/OG), harness side.




- Measure the resistance between the DSM C341c-26, circuit 915 (PK/LB), harness side and the DLC C251-10, circuit 915 (PK/LB), harness side.




- Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to H4.

No
REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

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H4 CHECK FOR CORRECT DSM OPERATION


- Disconnect all the DSM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the DSM 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. 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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