Pinpoint Test Z: Open PSCM (Power Steering Control Module) Fuse(S)

Refer to POWER STEERING CONTROLS for schematic and connector information.

Normal Operation and Fault Conditions 

REFER to: Power Steering - System Operation and Component Description 

Description 

• Description 
• There are 2 power sources for the PSCM, the high current power steering fuse, and the low current power steering fuse. Refer to the wiring diagrams to review the PSCM circuit for both the high current and low current fuse locations as well as the associated power and ground wiring. Open power steering fuse can occur when the power or ground wiring is shorted against another component or water intrusion in the respective connectors or connections.

Pinpoint Test Applicability 

• Pinpoint Test Applicability 
• This test applies to the following diagnostic concerns:
• Open PSCM fuse(s)

This test DOES NOT apply to any other DTC or symptom.

Diagnostic Strategy 

• Diagnostic Strategy 
• Using this test assumes that it is already known that the fuses are blown, which may also be accompanied by many Diagnostic Trouble Codes (DTCs). For DTC diagnostics refer to Diagnostic Trouble Code (DTC) Chart 
• The diagnostics of blown fuse(s) requires a thorough investigation of the power and ground side of the PSCM circuit, which includes power and ground wires, power and ground connections and/or connections, and PSCM power/ground connectors.
• Open fuse sources: 

  Open fuses can occur with any of the following: loose Fuses, loose grounds, loose high current battery junction box connections. Power or ground wiring being chaffed, pinched, cut by other components in the engine compartment (bracket sharp edges, wiring harness retainers loose, misrouting of wiring). Additionally water inside power and ground connectors will cause open PSCM circuit fuses.

Pinpoint Test Purpose 

• Pinpoint Test Purpose 
• To verify the PSCM, wiring harness, and connections are working correctly. This test also verifies the existence of a low battery state of charge.

Possible Sources 

• Fuse(s)
• Wiring, terminals or connectors

Visual Inspection and Pre-checks 

• Make sure all BJB and high-current BJB fuses related to the PSCM are OK.

1. This procedure must be completed using FDRS. Do not clear DTCs until the FDRS procedure has completed. To complete the diagnosis, navigate to the FDRS Guided Routine tab and carry out the procedure Electronic Power Assist Steering (EPAS) Invalid or Missing Controller Area Network (CAN) Data