LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lincoln >> 2018 >> Navigator Select, RWD >> Repair and Diagnosis >> Steering >> Electronic Steering >> EPAS Guided Routine Testing >> Pinpoint Tests >> Pinpoint Test AG: ABS Module Steering Angle Sensor Concerns With The PSCM - Electrical >> Possible Causes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Possible Causes

CAUTION: Use the correct probe adapter(s) when taking measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
NOTE: Refer to POWER STEERING CONTROLS for schematic and connector information.
NOTE: Failure to disconnect the battery when instructed results in false resistance readings.
  1. AGI: VERIFY BATTERY VOLTAGE LEVELS 
    • Inspect the battery connections and battery wiring. Refer to BATTERY, MOUNTING AND CABLES .
      • Verify the connections are clean and tight.
      • Verify the connections and cables are free from corrosion, cuts, and other damage.
    • Inspect the generator connections and generator wiring. Refer to GENERATOR AND REGULATOR .
      • Verify the connections are clean and tight.
      • Verify the connections and cables are free from corrosion, cuts, and other damage.
    • Verify the battery and charging system are providing the correct voltage to the vehicle.
    • Are the battery, generator and wiring in good condition, and is the system providing the correct voltage? 
      Yes No
      Go to  AG2. DIAGNOSE and REPAIR the battery or charging system. REFER to CHARGING SYSTEM - GENERAL INFORMATION .
      Go to  AG2.
  2. AG2: RETRIEVE THE PSCM DTCS 
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Drive the vehicle, attempt to replicate the customers driving conditions.
    • Carry out the PSCM self-test.
    • Does the PSCM respond to the diagnostic scan tool? 
      Yes No
      Go to  AG3. GO to PINPOINT TEST A .
  3. AG3: CHECK THE PSCM FOR INTERNAL FAULTS OR PROGRAMMING FAULTS 
    • Ignition ON, engine OFF.
    • Carry out the PSCM self-test.
      NOTE: This question does not apply to DTCs in history.
    • Are any of the following DTCs present in the PSCM; C102D, C1B00, C200B, C200C, C200D, P07AE, U2100, U2011, or U3000? 
      Yes No
      DIAGNOSE the PSCM DTCs. GO to the PSCM DTC Chart. Go to  AG4.
  4. AG4: CHECK THE PSCM FOR COMMUNICATION FAULTS OR INVALID DATA FAULTS 
    • Using the results from the previous step, determine if any lost communication, invalid data or voltage DTCs are present in the PSCM.
      • Lost communication DTCs indicate the PSCM is missing messages from another module within a certain expected time frame.
      • Invalid data DTCs indicate the PSCM received messages from another module but the data in the message is outside the expected content.
      • Voltage DTCs indicate the PSCM received voltages outside the expected range.
      PSCM COMMUNICATION AND INVALID DATA DTCS

      Lost Communication DTCs Invalid Data DTCs Voltage DTCs Control Module DTCs
      U0100 U0401 B1304 U3001
      U0102 U0403 U3003  
      U0121 U0415    
      U0122 U0416    
      U0126 U0422    
      U0140 U0423    
      U0151 U0428    
      U0155 U0452    
      U0159 U045A    
      U019B U053B    
      U0212 U053C    
      U023A U0553    
      U023B U0554    
      U0252      
    • Are any of the DTCs from the above table either currently or previously present in the PSCM? 
      Yes No
      If any communication or invalid data DTCs are present without any voltage DTCs, Go to  AG9.
      If ANY voltage DTCs are present, Go to  AG5.      		 Go to  AG5.
  5. AG5: CHECK THE PSCM FOR VOLTAGE FAULTS 
    • Using the results from the previous step, determine if any voltage DTCs are present in the PSCM.
      • These DTCs indicate the vehicle voltage levels delivered to PSCM were either interrupted, lower than the specific threshold range or higher than the specific threshold range the PSCM expects to receive.
    • Is DTC U3001 or U3003 either currently or previously present in the PSCM? 
      Yes No
      Go to  AG6. The PSCM circuit is working correctly at this time and is not a root cause of the ABS module DTC or symptom.
      Go to  AG9.
  6. AG6: PSCM CIRCUIT VERIFICATION - FUSES 
    NOTE: Refer to POWER STEERING CONTROLS for schematic and connector information.
    • Inspect the high-current BJB PSCM mega-fuse and BJB PSCM fuse.
      • Make sure both fuses are fully seated.
      • Make sure both fuses are not open.
      • Make sure both fuses are undamaged.
    • Are both fuses fully seated, undamaged and not open? 
      Yes No
      Go to  AG7. REINSTALL or INSTALL new fuses as necessary.
      Go to  AG7.
  7. AG7: PSCM CIRCUIT VERIFICATION - POWER WIRING AND CONNECTIONS 
    NOTE: Refer to POWER STEERING CONTROLS for schematic and connector information.
    • Visually check both power wiring and ground wiring for chaffing or pinching on other components.
    • Verify the power and ground connections are clean, fully seated or tightened, and free of corrosion.
    • Are the power and ground wiring and connections free from damage and correctly seated and tightened? 
      Yes No
      Go to  AG8. REPAIR or INSTALL new connectors or wiring as necessary.
      Go to  AG8.
  8. AG8: PSCM CIRCUIT VERIFICATION - POWER AND GROUND INTERNAL CIRCUIT CHECK 
    NOTE: This test verifies whether there is unseen, internal damage to the wiring harness.
    • 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.
    • Ignition ON, engine running.
    • 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:
      (+) Vehicle Battery (-) Vehicle Battery
      Positive terminal Negative terminal
    • 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 voltage differ by more than 1.5 volts? 
      Yes No
      INSTALL a new PSCM wiring harness. REPEAT this pinpoint test step to verify the new harness is also free from internal damage.
      If the voltage concerns are resolved, Go to  AG11.
      If the communication concerns are still present, Go to  AG9.      		 The PSCM power and ground circuits are working correctly at this time and are not root cause of the ABS module DTC or symptom.
      If communication or invalid data DTCs are present in the PSCM, Go to  AG9.
      If communication or invalid data DTCs are NOT present in the PSCM, Go to  AG11.
  9. AG9: PSCM CIRCUIT VERIFICATION - COMMUNICATION CONNECTIONS 
    NOTE: Refer to POWER STEERING CONTROLS for schematic and connector information.
    NOTE: The PSCM receives messages from other modules through 2 connectors connected to the HS-CAN wiring:
    • PSCM connector, C1436B pin-3, at the steering gear carries messages to and from the steering gear.
    • In-line connectors C210, C314 and C1046 carry messages to and from the vehicle network.
    • Ignition OFF.
    • PSCM_B connector disconnected. (C1463B)
    • Disconnect in-line electrical connectors C210, C314 and C1046.
    • Inspect all disconnected electrical connectors for the following:
      • Pushed-out pins, loose pins, spread terminals, water ingress or corrosion.
      • Missing or loose latches, broken or cracked connector housings.
    • Inspect the HS-CAN wiring for:
      • Pinched or cut wiring under brackets, air cleaner boxes, battery trays, engine pulleys, etc.
      • Loose wiring harness anchoring locations in the engine compartment.
    • Repair connectors or wiring as required.
    • PSCM_B connector connected. (C1463B) Make sure the connector seats and latches correctly.
    • Connect all disconnected electrical connectors. Make sure the connectors seat and latch correctly.
    • Ignition ON, engine OFF.
    • Clear the PSCM DTCs.
    • Drive the vehicle, attempt to replicate the customers driving conditions.
    • Carry out the PSCM self-test.
      NOTE: This question does not apply to DTCs in history.
    • Are there any lost communication or invalid data DTCs currently present and active in the PSCM? 
      Yes No
      Go to  AG10. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
      Go to  AG11.
  10. AG10: PSCM CIRCUIT VERIFICATION - COMMUNICATION WIRING 
    • Ignition OFF.
    • Visually Inspect the HS-CAN wiring is not pinched, chaffed, chewed by animals, damaged near or under the battery tray or other nearby components.
    • Disconnect the battery negative cable. Refer to the BATTERY, MOUNTING AND CABLES .
    • DLC connector disconnected. (C251)
    • PSCM_B connector disconnected. (C1463B)
    • Measure the resistance between:
      (+) PSCM_B (C1463B) Connector, Harness Side (-) DLC (C251) Connector, Harness Side
      CAN- - VDB26 (GRAY/BLUE) - Pin 3 CAN- - VDB05 - Pin 19
      CAN+ - VDB25 (GREEN/ORANGE) - Pin 2 CAN+ - VDB04 - Pin 20
    • Measure the resistance between:
      (+) PSCM_A (C1463A) Connector, Harness Side (-) DLC (C251) Connector, Harness Side
      CAN+ CAN+ - VDB04 - Pin 20
      CAN- CAN- - VDB05 - Pin 19
    • Measure the resistance between:
      (+) PSCM_D Connector, Harness Side (-) DLC (C251) Connector, Harness Side
      CAN+ CAN+ - VDB04 - Pin 20
      CAN- CAN- - VDB05 - Pin 19
    • Is the resistance less than 3 ohms? 
      Yes No
      The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
      Go to  AG11.      		 REPAIR the circuit.
      Go to  AG11.
  11. AG11: CHECK FOR ABS MODULE AND PSCM DTCS 
    • Ignition ON, engine OFF.
    • Carry out the PSCM self-test.
    • Carry out the ABS self-test.
      NOTE: This question does not apply to DTCs in history.
    • Are any lost communication or invalid data DTCs currently present and active in the PSCM or are any C006B:xx or C0051: xx DTCs currently present and active in the ABS module? 
      Yes No
      The PSCM wiring harness circuit evaluation is complete and not contributing to the ABS module DTC or symptom.
      GO to the corresponding to the module name in the remaining lost communication or invalid data codes to continue the diagnostics.      		 The PSCM wiring harness circuit adjustments or repairs have resolved the ABS module DTC or symptom concerns with the PSCM.
scientia non olet · About LEMON Manuals