Pinpoint Test I: The Power Steering Control Module (PSCM) Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test I: The Power Steering Control Module (PSCM) 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 43, Power Steering Controls for schematic and connector information. Diagrams By Number

Normal Operation

The PSCM communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- PSCM

PINPOINT TEST I: THE PSCM 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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I1 CHECK THE PSCM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

- Ignition OFF.
- Disconnect: PSCM C2368A and C2368B.
- Ignition ON.
- Measure the voltage between the PSCM C2368A-1, circuit SBF02 (YE/RD) harness side and ground.




- Measure the voltage between the PSCM C2368B-5, circuit CBP21 (BU/GY) harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to I2.

No
VERIFY the Battery Junction Box (BJB) fuse mega 2 (60A) and Central Junction Box (CJB) fuse 21 (10A) 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. Diagrams By Number

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I2 CHECK THE PSCM GROUND CIRCUITS FOR AN OPEN

- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: PSCM C2368C.
- Measure the resistance between the PSCM 2368C-1, circuit GD120 (BK/GN), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to I3.

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

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I3 CHECK THE HS-CAN CIRCUITS BETWEEN THE PSCM AND THE DLC FOR AN OPEN

- Measure the resistance between the PSCM C2368B-2, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.




- Measure the resistance between the PSCM C2368B-6, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), 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.

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I4 CHECK FOR CORRECT PSCM OPERATION

- Disconnect the PSCM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the PSCM 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 PSCM. 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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