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PSCM Circuit Information

WARNING: This page is about a different car, the 2020 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

Refer to the Power Steering Controls wiring diagrams 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-B Connector - C1463B
G11676842Courtesy of FORD MOTOR CO.

Harness Side

Circuit Pin
HS-CAN2- (High Speed Controller Area Network 2 Low) - VDB26 3 (GRAY)
HS-CAN2+ (High Speed Controller Area Network 2 High) - VDB25 2 (GREEN)
Fig 2: Gateway Module A (GWM) Connector - C2431
G13379245Courtesy of FORD MOTOR CO.

Harness Side

Circuit Pin
HS-CAN2- (High Speed Controller Area Network 2 Low) - VDB26 17 (GRAY)
HS-CAN2+ (High Speed Controller Area Network 2 High) - VDB25 18 (GREEN)
  1. BT1: VERIFY PSCM DTC 
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Ignition ON, engine running.

    Carry out the PSCM self-test.

    • Is DTC U0253:xx currently present and active in the PSCM? 
      Yes No
      Go to  BT2. If the PSCM does NOT list DTC U0253 Lost Communication With The APIM, DISCONTINUE this test and REFER to the DTC Chart for diagnostic direction.
  2. BT2: CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM VOLTAGE 
    • Ignition ON, engine OFF.
    • Refer to the Charging System General Information article 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 No
      Go to  BT3. INSTALL a new 12-volt battery. REFER to the Battery, Mounting and Cables article.
      Go to  BT3.
  3. BT3: 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 the other modules into the 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 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.
    • 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.
    • Ignition ON, engine running.

    Carry out the PSCM self-test.

    • Is DTC U0253:xx currently present and active in the PSCM? 
      Yes No
      Go to  BT4. 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.
  4. BT4: CHECK THE HS-CAN CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • GWM connector disconnected. (C2431)
    • PSCM_B connector disconnected. (C1463B)
    • Measure the resistance between:
      (+) PSCM_B (C1463B) Connector, Harness Side (-) GWM (C2431), Harness Side
      HS-CAN2- - VDB26 (GRAY) - Pin 3 HS-CAN2- - VDB26 - Pin 17
      HS-CAN2+ - VDB25 (GREEN) - Pin 2 HS-CAN2+ - VDB25 - Pin 18
    • Measure the resistance between:
  5. BT5: RECHECK FOR PSCM DTC U0253:XX 
    • PSCM_B connector connected. (C1463B) Make sure the connector seats and latches correctly.
    • GWM connector connected. (C2431) Make sure the connector seats and latches correctly.
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Ignition OFF.
    • Ignition ON, engine running.

    Carry out the PSCM self-test.

    • Is DTC U0253:xx currently present and active in the PSCM? 
      Yes No
      The PSCM HS-CAN circuits are working correctly at this time.
      RETRIEVE and RECORD all APIM DTCs. REFER to Diagnosis and Testing in the Information and Entertainment System article and DIAGNOSE the APIM.      		 If the PSCM no longer lists DTC U0253:xx, the concern was repaired during this pinpoint test and the PSCM HS-CAN circuits are working correctly at this time.
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