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Pinpoint Test BD: PSCM (Power Steering Control Module) DTC (Diagnostic Trouble Code) U0554:00 Invalid Data Received From The Accessory Protocol Interface Module

  1. 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 
    • The PSCM monitors the FD-CAN when the voltage to the PSCM is greater than 10 volts and there are no Diagnostic Trouble Codes (DTCs) present inhibiting PSCM operation.

    Pinpoint Test Applicability 

    • Pinpoint Test Applicability 
    • This test applies to PSCMDTC U0554 Invalid Data Received from the APIM only. It does not apply to any other module except the PSCM.

    DTC Diagnostic Strategy 

    • DTC Diagnostic Strategy 
    • If the module DTC list results in a large number of Diagnostic Trouble Codes (DTCs), diagnose all module hard faults first (C102D, C1B00, C200B, C200C, C200D, U2011 and U3000) before diagnosing any network faults (lost communication or invalid data). If voltage concern Diagnostic Trouble Codes (DTCs) are present, diagnose those after any module hard faults and before any network faults. Diagnose all current and active Diagnostic Trouble Codes (DTCs) before diagnosing any historic Diagnostic Trouble Codes (DTCs).

    Pinpoint Test Purpose 

    • Pinpoint Test Purpose 
    • To direct the diagnosis to the module and associated circuit sending the faulty or unknown information in the messages.

    Diagnostic Aids 

    • Diagnostic Aids 
    • For additional information on the messages sent to the PSCM from the APIM module, refer Network Message Chart .
    • DTC U0554:00 indicates a concern with the lane information sent from the APIM. The module reporting this DTC is not the problem module. Do not install a new PSCM as part of the repair for PSCMDTC U0554:00.
    • The presence of DTC U0554:00 may prevent the trailer backup optional feature from activating. If the DTC sets during an backup event, the event may be terminated and the feature may be deactivated.

    DTC Fault Trigger Conditions 

    DTC Description Fault Trigger Condition
    PSCM U0554:00 Invalid Data Received From Accessory Protocol Interface Module: No Sub Type Information This DTC is set if the PSCM receives an "fault" or "unknown" message from the APIM instead of valid information.

    Possible Causes 

    • FD-CAN concern
    • APIM
    • This DTC sets when the PSCM does not receive the APIM messages within a certain time frame. This can occur if the APIM wiring harness or electrical connectors are loose or damaged, or if the vehicle battery state of charge levels are low. Consult the DTC Index for additional information if needed.

  2. BD1 VERIFY PSCM (POWER STEERING CONTROL MODULE) DTC (DIAGNOSTIC TROUBLE CODE)

    • Ignition ON.

    • Clear the PSCMDTC s.

    • Ignition OFF.

    • Ignition ON.

    • Carry out the PSCM self-test.

    Is DTC U0554:00 currently present and active in the PSCM ' 

    Yes  GO to  BD2
    No  If the PSCM does NOT list DTC U0554 Lost Communication With The APIM, DISCONTINUE this test and REFER to the appropriate DTC Chart for diagnostic direction.

  3. BD2 CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM VOLTAGE

    • Ignition ON.

    • Refer to the appropriate Battery and Charging System service information and carry out Pinpoint Test A: Battery Condition Test (battery state of charge).

    Did the battery pass the condition test (battery state of charge)? 

    Yes  GO to  BD3
    No  INSTALL a new 12-volt battery. REFER to: Battery . GO to  BD3

  4. BD3 INSPECT THE PSCM (POWER STEERING CONTROL MODULE) COMMUNICATION WIRING AND CONNECTORS

    • Ignition OFF.

    • Inspect all disconnected connectors for:

      • Pushed-out pins, loose pins, bent pins, spread terminals, water ingress and corrosion.
      • Missing or loose latches, broken or cracked connector housings.
      • VDB wiring for pinched or cut wiring under brackets, air cleaner boxes, battery trays, engine pulleys, etc.

    • Inspect the VDB wiring for pinched or cut wiring under brackets, air cleaner boxes, battery trays, engine pulleys, etc.

    • Inspect the VDB wiring harness anchors for coming loose from anchoring locations in the engine compartment.

    • Repair the connectors or wiring as necessary.

    • Ignition ON.

    • Clear the PSCMDTC s.

    • Ignition OFF.

    • Ignition ON.

    • Carry out the PSCM self-test.

    Is DTC U0554:00 currently present and active in the PSCM ' 

    Yes  GO to  BD4
    No  The concern is not present at this time and may have been set due to a loose or damaged electrical connector. The test is complete, no further action is required.

  5. BD4 CHECK THE FD-CAN (FLEXIBLE DATA RATE CONTROLLER AREA NETWORK) CIRCUITS FOR AN OPEN

    • Ignition OFF.

    • Disconnect GWM connector, C2431A.

    • Disconnect PSCM _A connector, C1467A.

    Are the resistances less than 3 ohms? 

    Yes  The FD-CAN circuits are OK, GO to  BD5
    No  REPAIR the circuit.

  6. BD5 RECHECK FOR PSCM (POWER STEERING CONTROL MODULE) DTC (DIAGNOSTIC TROUBLE CODE) U0554:XX

    • Connect PSCM _A connector, C1467A. Make sure the connector seats and latches correctly.

    • Connect GWM connector, C2431A. Make sure the connector seats and latches correctly.

    • Ignition ON.

    • Clear the PSCMDTC s.

    • Ignition OFF.

    • Ignition ON.

    • Carry out the PSCM self-test.

    Is DTC U0554:00 currently present and active in the PSCM ' 

    Yes  The PSCMFD-CAN circuits are working correctly at this time. RETRIEVE and RECORD all APIMDTCs. REFER to: Information and Entertainment System .
    DIAGNOSE the APIM.
    No  If the PSCM no longer lists DTC U0554::xx, the concern was repaired during this pinpoint test and the PSCMFD-CAN circuits are working correctly at this time.
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