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PSCM Circuit Information

Refer to Power Steering Controls in OEM Wiring Diagram article, for schematic and connector information.

Refer to Steering GSB for additional connector and wiring inspection tips.

NOTE: Use the correct probe adapters when making measurements. Failure to use the correct probe adapters may cause damage to the connector.
Fig 1: PSCM-A Connector (C1463A)
G11676842Courtesy of FORD MOTOR CO.
CIRCUIT AND PIN DESCRIPTION

Circuit Pin
CAN- (Controller Area Network) - VDB26 3 (GRAY/BLUE)
CAN+ (Controller Area Network) - VDB25 2 (GREEN/ORANGE)
Fig 2: Data Link Connector (C251)
G12970749Courtesy of FORD MOTOR CO.
CIRCUIT AND PIN DESCRIPTION

Circuit Pin
CAN- (Controller Area Network) - VDB26 11 (GRAY/BLUE)
CAN+ (Controller Area Network) - VDB25 3 (GREEN/ORANGE)
  1. AI1: VERIFY PSCM DTC 
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Wait at least 90 seconds for the modules to completely shut off.
    • Ignition ON, engine running.
    • Carry out the PSCM self-test.
    • Is DTC U0102 currently present and active in the PSCM? 
    Yes No
    Go to  AI2. If the PSCM does NOT list DTC U0102 Lost Communication With Transfer Case Control Module, DISCONTINUE this test and REFER to the DTC Index  for diagnostic direction.
  2. AI2: INSPECT THE PSCM COMMUNICATION WIRING AND CONNECTORS 
    NOTE: The PSCM receives messages from other modules through 2 connectors: the PSCM - A (or B) 3-pin connector at the gear and the multi-pin in-line connector in the engine compartment. The in-line connector receives messages from there other modules into the acronym>PSCM wiring harness. The PSCM wiring harness uses the VDB wiring to carry the messages from the in-line connector to the PSCM - A (or B) 3-pin connector. If any of the connector pins or VDB communication wires are loose or damaged, the PSCM cannot properly receive messages from other modules.
    • Ignition OFF.
    • Disconnect PSCM-A (or B) 3-pin and the in-line electrical connectors.
    • Inspect both connectors for:
      • pushed-out pins, loose 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.
    • Connect PSCM-A (or B) 3-pin and the in-line electrical connectors.
      • Verify connectors are solidly latched and connected without water ingress gaps.
      • Verify wiring harness anchors are solidly pushed into retaining holes, etc.
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Wait at least 90 seconds for the modules to completely shut off.
    • Ignition ON, engine running.
    • Carry out the PSCM self-test.
    • Is DTC U0102 present in the PSCM? 
    Yes No
    Go to  AI3. 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.
  3. AI3: CHECK THE HS-CAN CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • DLC connector disconnected. (C251)
    • PSCM_A connector disconnected. (C1463A)
    • Measure the resistance between:
      (+) PSCM_A (C1463A) Connector, Harness Side (-) DLC (C251) Connector, Harness Side
      CAN- - VDB26 (GRAY/BLUE) - Pin 3 CAN- - VDB26 - Pin 11
      CAN+ - VDB25 (GREEN/ORANGE) - Pin 2 CAN+ - VDB25 - Pin 3
    • Measure the resistance between:
      (+) PSCM_B (C1436B) Connector, Harness Side (-) DLC (C251) Connector, Harness Side
      CAN- CAN- - VDB26 - Pin 11
      CAN+ CAN+ - VDB25 - Pin 3
    • Are the resistances less than 3 ohms? 
    Yes No
    The HS-CAN circuits are OK, Go to  AI4. REPAIR the circuit.
  4. AI4: RECHECK FOR PSCM DTC U0102 
    • PSCM_A connector connected. (C1463A) Make sure the connector seats and latches correctly.
    • DLC connector connected. (C251) Make sure the connector seats and latches correctly.
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Wait at least 90 seconds for the modules to completely shut off.
    • Ignition ON, engine running.
    • Carry out the PSCM self-test.
    • Is DTC U0102 currently present and active in the PSCM? 
    Yes No
    The PSCM HS-CAN circuits are working correctly at this time. RETRIEVE and RECORD all PCM DTCs.
    REFER to the applicable Engine Controls article or Diagnosis and Testing in applicable Electronic Engine Controls article and DIAGNOSE the PCM.    		 If the PSCM no longer lists DTC U0102, the concern was repaired during this pinpoint test and the PSCM HS-CAN circuits are working correctly at this time.
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