PSCM Circuit Information

Refer to Power Steering Controls wiring diagrams for schematic and connector information.

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

Fig 1: High Current Battery Junction Box-B (HC-BJB-B) Assembly Connector - C1617B

Courtesy of FORD MOTOR CO.

Harness Side

Fig 2: PSCM-A Connector - C225A

Courtesy of FORD MOTOR CO.

Harness Side

Fig 3: PSCM-B Connector - C225B

Courtesy of FORD MOTOR CO.

Harness Side

Fig 4: Gateway Module A (GWM) Connector - C2431

Courtesy of FORD MOTOR CO.

Harness Side

Fig 5: Battery Junction Box-B (BJB-B) Module Connector - C1035B

Courtesy of FORD MOTOR CO.

Harness Side

1. BK1: CHECK PSCM COMMUNICATION WITH THE DIAGNOSTIC SCAN TOOL 
   • Start the vehicle.
     • Make sure the engine ready indicator is illuminated.
   • Retrieve the continuous memory DTCs.
   • Does the diagnostic scan tool communicate with the PSCM and retrieve DTCs? 

   Yes	No
   Go to  BK2.	Go to  BK3.

2. BK2: CHECK ALL MODULES FOR DTC U0131:XX 
   • Review the DTCs retrieved in the previous step.
   • Is DTC U0131:xx present in any module? 

   Yes	No
   Go to  BK3.	If DTC U0131:XX is not present in any module, DISCONTINUE this test.

3. BK3: 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  BK4.	INSTALL a new 12-volt battery. REFER to the Battery, Mounting and Cables article.

4. BK4: CHECK THE PSCM BATTERY AND IGNITION VOLTAGE 
   • Ignition OFF.
   • PSCM_A connector disconnected. (C225A)
   • PSCM_B connector disconnected. (C225B)
   • Ignition ON, engine OFF.
   • Measure the voltage between:

   (+) PSCM_A (C225A) Connector, Harness Side	(-)
   B+	Ground
   IGN START/RUN - CBB22 (GREEN/ORANGE) - Pin 1	Ground

   • Measure the voltage between:

   (+) PSCM_B (C225B) Connector, Harness Side	(-)
   B+ - SBF03 (BLUE/RED) - Pin 1	Ground
   IGN START/RUN	Ground

   • Measure the voltage between:

   (+) PSCM C Connector, Harness Side	(-)
   B+	Ground

   • Are the voltages greater than 11 volts? 

   Yes	No
   Go to  BK5.	VERIFY all PSCM related BJB and high-current BJB fuses are OK. If the fuses are not OK, REFER to the Power Steering Controls wiring diagrams to identify the possible cause of the circuit short. If the fuses are OK, REPAIR the circuit.

5. BK5: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN 
   • Ignition OFF.
   • Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in the Battery, Mounting and Cables article.
   • Measure the resistance between:

   (+) PSCM C Connector, Harness Side	(-)
   GND	Ground

   • Measure the resistance between:

   (+) PSCM_B (C225B) Connector, Harness Side	(-)
   GND - GD233 (BLACK) - Pin 2	Ground

   • Measure the resistance between:

     (+) PSCM C Connector, Harness Side	(-)
     GND	Ground

   • Is the resistance less than 3 ohms? 

   Yes	No
   Go to  BK6.	REPAIR the circuit.

6. BK6: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN 
   • GWM connector disconnected. (C2431)
   • Measure the resistance between:

   (+) PSCM_A (C225A) Connector, Harness Side	(-) GWM (C2431), Harness Side
   HS-CAN2- - VDB26 (GRAY/BLUE) - Pin 3	HS-CAN2- - VDB26 - Pin 17
   HS-CAN2+ - VDB25 (GREEN/ORANGE) - Pin 2	HS-CAN2+ - VDB25 - Pin 18
   FD-CAN-	FD-CAN-
   FD-CAN+	FD-CAN+

   • Measure the resistance between:

   (+) PSCM_B (C225B) Connector, Harness Side	(-)
   HS-CAN2-	HS-CAN2- - VDB26 - Pin 17
   HS-CAN2+	HS-CAN2+ - VDB25 - Pin 18

   • Are the resistances less than 3 ohms? 

   Yes	No
   Go to  BK7.	REPAIR the circuit.

7. BK7: VERIFY ALL PSCM WIRING CONNECTIONS 
   • Ignition OFF.
   • Disconnect all PSCM wiring harness in-line electrical connectors. Refer to Power Steering Controls wiring diagrams connector information. Refer to the PSCM Connection GSB for additional connection checks.
   • Using a good light source, inspect all PSCM and related in-line electrical connectors for:
     • corrosion - install a new connector or terminal and clean the module pins.
     • damaged or bent pins - install new terminals or pins.
     • pushed-out pins - install new pins as necessary.
     • spread terminals - install new terminals as necessary.
   • PSCM_A connector connected. (C225A) Make sure the connector seats and latches correctly.
   • PSCM_B connector connected. (C225B) Make sure the connector seats and latches correctly.
   • GWM connector connected. (C2431) Make sure the connector seats and latches correctly.
   • Connect all PSCM wire harness in-line electrical connectors. Make sure they seat and latch correctly.
   • Connect the battery negative cable. Refer to the General Procedure, Battery Disconnect in the Battery, Mounting and Cables article.
   • Ignition ON, engine OFF.
   • Using a diagnostic scan tool, clear DTC U0131:xx from the reporting module.
   • Ignition OFF.
   • Start the vehicle.
     • Make sure the engine ready indicator is illuminated.
   • Test drive the vehicle.
   • Is a lack of assist, intermittent assist or inconsistent assist still present? 

   Yes	No
   Go to  BK8.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded PSCM electrical connector or a wiring harness in-line electrical connector and was repaired during this procedure.

8. BK8: CHECK FOR CORRECT PSCM POWER AND GROUND JOINT OPERATION 
   • Ignition OFF.
   • Disconnect the PSCM ground joint connection.
   • HC-BJB_B Assembly connector disconnected. (C1617B)
   • BJB_B Module connector disconnected. (C1035B)
   • Inspect the high-current BJB connection, clean or repair as necessary. Refer to Power Steering Controls wiring diagrams high-current BJB joint information.
   • Inspect the PSCM ground joint connection, clean or repair as necessary. Refer to Power Steering Controls wiring diagrams high-current PSCM ground joint information.
   • Connect the PSCM ground joint connection. Make sure the connection is clean, tight and not cross-threaded.
   • Connect the high-current BJB 12-volt joint connection. Make sure the connection is clean, tight and not cross-threaded.
   • BJB_B Module connector disconnected. (C1035B) Make sure the connector seats and latches correctly.
   • HC-BJB_B Assembly connector connected. (C1617B) Make sure the connection is clean, tight and not cross-threaded.
   • Ignition ON, engine OFF.
   • Using a diagnostic scan tool, clear DTC U0131:xx from the reporting module.
   • Ignition OFF.
   • Start the vehicle.
     • Make sure the engine ready indicator is illuminated.
   • Test drive the vehicle above 20 km/h (12 mph) for at least 5 minutes.
   • Is a lack of assist, intermittent assist or inconsistent assist still present? 

   Yes	No
   Go to  BK9.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded PSCM electrical connector or a wiring harness in-line electrical connector and was repaired during this procedure.

9. BK9: CHECK FOR INTERMITTENT PSCM WIRING HARNESS POWER AND GROUND CIRCUIT OPERATION 
   • Start the vehicle.
     • Make sure the engine ready indicator is illuminated.
   • Make sure the front wheels are on the ground and the vehicle is not being supported by other means.
     • Make sure the front tires are clean and dry.
     • Make sure the ground under the front tires is clean and dry.
   • Take the following measurement while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.
   • Measure the voltage between:

   (+) 12 Volt Vehicle Battery	(-) 12 Volt Vehicle Battery
   Positive terminal	Negative terminal

   • Record the measured battery voltage.
   • View the following PID while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.
   • Using a diagnostic scan tool, view the PSCM battery voltage or main voltage PID.
   • Compare the measured battery voltage with the PID display.
   NOTE: If the scan tool cannot display the PID reading due to no communication with the PSCM, select the No Result/Action.
   • Do the measured battery voltage and the PID display differ by more than 1.5 volts? 

   Yes	No
   INSTALL a new PSCM wiring harness. Go to  BK10.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded PSCM electrical connector or a wiring harness in-line electrical connector and was repaired during this procedure.

10. BK10: VERIFY PSCM OPERATION 
    • Start the vehicle.
      • Make sure the engine ready indicator is illuminated.
    • Make sure the front wheels are on the ground and the vehicle is not being supported by other means.
      • Make sure the front tires are clean and dry.
      • Make sure the ground under the front tires is clean and dry.
    • Take the following measurement while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.
    • Measure the voltage between:

    (+) 12 Volt Vehicle Battery	(-) 12 Volt Vehicle Battery
    Positive terminal	Negative terminal

    • Record the measured battery voltage.
    • View the following PID while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.
    • Using a diagnostic scan tool, view the PSCM battery voltage or main voltage PID.
    • Compare the measured battery voltage with the PID display.
    • Do the measured battery voltage and the PID display differ by more than 1.5 volts? 

    Yes	No
    INSTALL a new PSCM wiring harness and CARRY OUT this step again. Go to  BK11.	The repair is complete.

11. BK11: VERIFY VEHICLE CONCERN 
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Start the vehicle.
      • Make sure the engine ready indicator is illuminated.
    • Test drive the vehicle.
    • Is a lack of assist, intermittent assist or inconsistent assist still present? 

    Yes	No
    For F-Super Duty, if HPAS diagnostics have been carried out, Go to  BK12. For F-Super Duty, if HPAS diagnostics have NOT been carried out, REFER to the Power Steering article and DIAGNOSE the HPAS system. For all others, Go to  BK12.	The repair is complete, no further action is required.

12. BK12: CHECK FOR APPLICABLE SERVICE ARTICLES 
    • Ignition OFF.
    • Check OASIS for any applicable TSB s, GSB s, SSM s or FSAs.
    • Does a service article exist for a lack of assist, intermittent or inconsistent assist condition? 

    Yes	No
    DISCONTINUE this test and FOLLOW the service article instructions.	INSTALL a new EPAS steering column. REFER to the Steering Column article. ORDER a replacement EPAS column and INCLUDE the RVC on the order form. If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.