Normal Operation
The PSCM wiring harness circuit provides 5 connections and 2 fuses: (1) threaded ground joint, (2) high-current BJB joint or connector, (3) in-line HS-CAN ignition signal connector, (4) power and ground connector at the PSCM, (5) HS-CAN ignition signal connector at the PSCM, (6) high-current BJB PSCM MEGA fuse, and (7) BJB ignition fuse. Specific circuit schematics are provided in Power Steering Controls in the appropriate OEM WIRING DIAGRAMS article. The ignition portion of the circuit is responsible for waking up the PSCM.
Concerns with the PSCM wiring harness or fuses may result in a loss of communication between the PSCM and other modules which may result in reduced steering assist. The purpose of the PSCM Wire Harness Circuit Integrity Test is to assist with the identification of the root cause of the following wiring circuit concerns:
- Other modules losing communication with the PSCM or the PSCM does not respond to the diagnostic scan tool - concerns with any of the PSCM 5 wiring harness connections or wires, 2 fuses or the charging system can trigger U0131 DTCs in other modules.
- PSCM losing communication with other modules - any concerns with the PSCM in-line electrical connectors, wiring or the PSCM B electrical connector or wiring can trigger DTC U0001, U0100, U0121, U0122, U0126, U0140, U0151, U0155, U0159, U019B or U023A. Any concerns with the other module can also result in the PSCM losing communication with another module.
- The PSCM voltage supply concerns - any concerns with the MEGA fuse, charging system, power & ground connections or wiring trigger DTC B1304 or U3003.
- Intermittent loss of assist - any attached connection or connector, wire, or fuse not firmly and tightly connected or seated can trigger an intermittent loss of assist.
If any of the DTCs listed in the table below are present, diagnose them before continuing with this pinpoint test.
STEERING GEAR MOUNTED EPAS - PSCM DTCS
| DTC | Description |
|---|---|
| C102D | High Friction Inside Power Steering |
| C1B00 | Steering Angle Sensor |
| C200B | Steering Shaft Torque Sensor 1 |
| C200C | Steering Shaft Torque Sensor 2 |
| C200D | Motor Rotation Angle Sensor |
| P061A | Internal Control Module Torque Performance |
| P160C | Control Module Software Performance |
| U0300 | Internal Control Module Software Incompatibility |
| U2011 | Motor |
| U2100 | Initial Configuration Not Complete |
| U3000 | Control Module |
PSCM-A Connector - C2368A
Harness Side
| Circuit | Pin |
|---|---|
| CAN- (Controller Area Network) - VDB05 | 6(WHITE) |
| CAN+ (Controller Area Network) - VDB04 | 2(WHITE/BLUE) |
| IGN START/RUN (Ignition START/RUN) - CBP27 | 5(GREEN/BROWN) |
PSCM-B Connector - C2368B
Harness Side
| Circuit | Pin |
|---|---|
| GND (Ground) - GD114 | 1(BLACK/BLUE) |
High-current Battery Junction Box Connector - C1617B
Harness Side
| Circuit | Pin |
|---|---|
| B+ (Battery Positive Voltage) - SDF02 | 1(YELLOW/RED) |
Data Link Connector (DLC) Connector - C251
Harness Side
| Circuit | Pin |
|---|---|
| CAN- (Controller Area Network) - VDB05 | 14(WHITE) |
| CAN+ (Controller Area Network) - VDB04 | 6(WHITE/BLUE) |
- A1: CHECK PSCM COMMUNICATION WITH THE DIAGNOSTIC SCAN TOOL
- Carry out the PSCM self-test.
- Does the diagnostic scan tool communicate with the PSCM and retrieve DTCs?
Yes No Go to A2. Go to A4. - A2: CHECK PSCM DTCS
- Review the DTCs retrieved in the previous step.
- Is DTC B1304:68, U0001 or U3003 present or are any Lost Communication DTCs present?
Yes No For the PSCM reporting DTC U0001 or U3003, Go to A4.
For other modules reporting lost communication with the PSCM (such as DTC U0131:XX), Go to A4.
For the PSCM reporting lost communication with other modules (such as DTCs U0121:00), Go to A3.If no DTCs are present in the PSCM, Go to A4.
If other PSCM DTCs are present with DTC B1304, U0001 or U3003, or with the lost communication concern,
DIAGNOSE all other PSCM DTCs before continuing with this pinpoint test. GO to the PSCM DTC/Symptom Selection . - A3: CHECK COMMUNICATION WITH OTHER (NOT PSCM) MODULES
- Using a diagnostic scan tool, attempt to carry out a self-test of the module reported to be not communicating with the PSCM in the previous step.
- Does the module communicate with the diagnostic scan tool?
Yes No If there are DTCs other than lost communication, invalid data or battery voltage in the non-communicating module,
REFER to the appropriate service information to diagnose the DTCs.
If there are only lost communication DTCs, invalid data DTCs, battery voltage DTCs or no DTCs in the non-communicating module, Go to A4.REFER to appropriate Module Configuration article to diagnose the no communication concern. - A4: CHECK THE BATTERY AND CHARGING SYSTEM VOLTAGE
- Ignition OFF.
- Are the battery and charging system operating correctly?
- A5: CHECK THE PSCM BATTERY BATTERY AND IGNITION VOLTAGE
- Ignition OFF.
- PSCM_A connector disconnected. (C2368A)
- PSCM_B connector disconnected. (C2368B)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) B+ Ground - Measure the voltage between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) IGN START/RUN Ground - Are the voltages greater than 11 volts?
Yes No Go to A6. Verify high-current BJB mega fuse 1 (80A) and BJB fuse 40 (5A) are OK. If the fuses are OK, REPAIR the circuit. If the fuses are not OK, REFER to the appropriate Wiring Diagrams article to identify the possible causes of the circuit short.
- A6: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in appropriate Battery, Mounting and Cables article.
- Measure the resistance between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) GND Ground - Is the resistance less than 3 Ohm?
Yes No Go to A7. REPAIR the circuit. - A7: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) DLC (C251) Connector, Harness Side CAN- CAN- - VDB05 - Pin 14 CAN+ CAN+ - VDB04 - Pin 6 - Are the resistances less than 3 Ohm?
Yes No Go to A20. REPAIR the circuit. - Measure the resistance between:
- A8: CHECK THE PSCM BATTERY BATTERY AND IGNITION VOLTAGE
- Ignition OFF.
- PSCM_A connector disconnected. (C2368A)
- PSCM_B connector disconnected. (C2368B)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) B+ Ground - Measure the voltage between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) IGN START/RUN - CBP27 (GREEN/BROWN) - Pin 5 Ground - Are the voltages greater than 11 volts?
Yes No Go to A9. VERIFY high-current BJB fuse 4 (100A) and BJB fuse 89 (5A) are OK. If the fuses are OK, REPAIR the circuit. If the fuses are not OK, REFER to the appropriate Wiring Diagrams to identify the possible causes of the circuit short.
- A9: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in appropriate Battery, Mounting and Cables article.
- Measure the resistance between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) GND - GD114 (BLACK/BLUE) - Pin 1 Ground - Is the resistance less than 3 Ohm?
Yes No Go to A10. REPAIR the circuit. - A10: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) DLC (C251) Connector, Harness Side CAN- - VDB05 (WHITE) - Pin 6 CAN- - VDB05 - Pin 14 CAN+ - VDB04 (WHITE/BLUE) - Pin 2 CAN+ - VDB04 - Pin 6 - Are the resistances less than 3 Ohm?
Yes No Go to A20. REPAIR the circuit. - Measure the resistance between:
- A11: CHECK THE PSCM BATTERY BATTERY AND IGNITION VOLTAGE
- Ignition OFF.
- PSCM_A connector disconnected. (C2368A)
- PSCM_B connector disconnected. (C2368B)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) B+ Ground - Measure the voltage between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) IGN START/RUN - CBP27 (GREEN/BROWN) - Pin 5 Ground - Are the voltages greater than 11 volts?
Yes No Go to A12. Verify high-current BJB fuse 6 (80A) and BJB fuse 19 (10A) are OK. If the fuses are OK, REPAIR the circuit. If the fuses are not OK, REFER to the appropriate Wiring Diagrams to identify the possible causes of the circuit short.
- A12: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in appropriate Battery, Mounting and Cables article.
- Measure the resistance between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) GND - GD114 (BLACK/BLUE) - Pin 1 Ground - Is the resistance less than 3 Ohm?
Yes No Go to A13. REPAIR the circuit. - A13: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) DLC (C251) Connector, Harness Side CAN- - VDB05 (WHITE) - Pin 6 CAN- - VDB05 - Pin 14 CAN+ - VDB04 (WHITE/BLUE) - Pin 2 CAN+ - VDB04 - Pin 6 - Are the resistances less than 3 Ohm?
Yes No Go to A20. REPAIR the circuit. - Measure the resistance between:
- A14: CHECK THE PSCM BATTERY BATTERY AND IGNITION VOLTAGE
- Ignition OFF.
- PSCM_A connector disconnected. (C2368A)
- PSCM_B connector disconnected. (C2368B)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) B+ Ground - Measure the voltage between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) IGN START/RUN Ground - Are the voltages greater than 11 volts?
Yes No Go to A15. VERIFY high-current BJB fuse 6 (70A) and BJB fuse 19 (10A) are OK.
If the fuses are OK, REPAIR the circuit.
If the fuses are not OK, REFER to the appropriate Wiring Diagrams manual to identify the possible causes of the circuit short. - A15: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in appropriate Battery, Mounting and Cables article.
- Measure the resistance between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) GND Ground - Is the resistance less than 3 Ohm?
Yes No Go to A16. REPAIR the circuit. - A16: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) DLC (C251) Connector, Harness Side CAN- CAN- - VDB05 - Pin 14 CAN+ CAN+ - VDB04 - Pin 6 - Are the resistances less than 3 Ohm?
Yes No Go to A20. REPAIR the circuit. - Measure the resistance between:
- A17: CHECK THE PSCM BATTERY BATTERY AND IGNITION VOLTAGE
- Ignition OFF.
- PSCM_A connector disconnected. (C2368A)
- PSCM_B connector disconnected. (C2368B)
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) B+ Ground - Measure the voltage between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) IGN START/RUN Ground - Are the voltages greater than 11 volts?
Yes No Go to A18. Verify high-current BJB 125 amp mega fuse and BJB fuse 18 (10A) are OK. If the fuses are OK, REFER to the appropriate Wiring Diagram to identify the possible causes of the circuit short.
- A18: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in appropriate Battery, Mounting and Cables article.
- Measure the resistance between:
(+) PSCM_A (C2368A) Connector, Harness Side (-) GND Ground - Is the resistance less than 3 Ohm?
Yes No Go to A19. REPAIR the circuit. - A19: CHECK THE PSCM HS-CAN CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) PSCM_B (C2368B) Connector, Harness Side (-) DLC (C251) Connector, Harness Side CAN- CAN- - VDB05 - Pin 14 CAN+ CAN+ - VDB04 - Pin 6 - Are the resistances less than 3 Ohm?
Yes No Go to A20. REPAIR the circuit. - Measure the resistance between:
- A20: VERIFY ALL PSCM WIRING CONNECTIONS
- Ignition OFF.
- Disconnect all PSCM wiring harness in-line electrical connectors. Refer to Power Steering Controls in the appropriate OEM WIRING DIAGRAMS article for connector information. Refer to the PSCM Connection General Service Bulletin 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. (C2368A)
- PSCM_B connector connected. (C2368B)
- Make sure both PSCM electrical connectors seat and latch 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 appropriate Battery, Mounting and Cables article.
- Clear the PSCM DTCs.
- Operate the system and verify the concern is present.
- Is the concern still present?
Yes No Go to A21. 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. - A21: CHECK FOR CORRECT PSCM POWER AND GROUND JOINT OPERATION
- Ignition OFF.
- Disconnect and inspect the PSCM ground joint connection, clean or repair as necessary. Refer to Power Steering Controls in the appropriate OEM WIRING DIAGRAMS article for ground joint information.
- Connect the PSCM ground joint connection. Make sure the connection is clean, tight and not cross-threaded.
- Clear the PSCM DTCs.
- Operate the system and verify the concern is present.
- Is the concern still present?
Yes No The concern may be an intermittent condition with the PSCM wiring harness which cannot be detected by voltage or resistance checks.
Go to A22.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. - A22: CHECK FOR INTERMITTENT PSCM WIRING HARNESS POWER AND GROUND CIRCUIT OPERATION
- 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.
- Access the PSCM and monitor the MOD_SUP_V (VOLT) 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 A23.Go to A24. - Make sure the front wheels are on the ground and the vehicle is not being supported by other means.
- A23: VERIFY PSCM OPERATION
- 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.
- Access the PSCM and monitor the MOD_SUP_V (VOLT) 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 Go to A24. The repair is complete. - Make sure the front wheels are on the ground and the vehicle is not being supported by other means.
- A24: 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 this concern?
| Yes | No |
|---|---|
| DISCONTINUE this test and FOLLOW the service article instructions. | INSTALL a new EPAS gear. REFER to appropriate Power Steering article. ORDER a replacement PSCM and INCLUDE the RVC on the form. If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form. |