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Home >> Ford >> 2022 >> Transit Connect Titanium, Gas/Ethanol >> Repair and Diagnosis >> External Pages >> Different car >> Section 743 (Abs Guided Routine - Pinpoint Tests A - AZ) >> Pinpoint Tests Ab: Wheel Speed Sensor Erratic Signal DTCS >> Possible Causes

Possible Causes

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CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
Fig 1: Anti-Lock Brake System-A (ABS-A) Module Connector - C135A
G13726212Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
Fig 2: Anti-Lock Brake System-B (ABS-B) Module Connector - C135B
G13726213Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
Fig 3: Left Front Wheel Speed Sensor Connector - C150
G13726214Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
LF WSS HI (Left Front Wheel Speed Sensor High) - VCA03 1 (VIOLET/WHITE)
LF WSS LO (Left Front Wheel Speed Sensor Low) - RCA17 2 (YELLOW) 2 (YELLOW)
Fig 4: Right Front Wheel Speed Sensor Connector - C160
G13726215Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
RF WSS HI (Right Front Wheel Speed Sensor HI) - VCA05 1 (GRAY/VIOLET)
RF WSS LO (Right Front Wheel Speed Sensor Low) - RCA19 2 (VIOLET)
Fig 5: Left Rear Wheel Speed Sensor Connector - C440
G13726216Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
LR WSS HI (Left Rear Wheel Speed Sensor High) - VCA04 1 (BLUE/ORANGE)
LR WSS LO (Left Rear Wheel Speed Sensor Low) - RCA18 2 (BROWN/GREEN)
Fig 6: Right Rear Wheel Speed Sensor Connector - C426
G13726217Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit Pin
RR WSS HI (Right Rear Wheel Speed Sensor High) - VCA06 1 (WHITE/ORANGE)
RR WSS LO (Right Rear Wheel Speed Sensor Low) - RCA20 2 (BROWN)
  1. AB1: Check For ABS Module DTCs 
    • Put the ABS module in sleep mode by performing the following steps:
      • With ALL doors closed, set the ignition from ON to OFF.
      • Disconnect the diagnostic scan tool.
      • Open the door, exit the vehicle and close the door.
      • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
    • Ignition ON, engine OFF.

    Carry out the ABS self-test.

    • Is DTC C003x:29 or C003x:64 present?
    Yes No
    Go to  AB2. For DTC C0031:07, C0034:07, C0037:07, C003A:07, C0031:2F, C0034:2F, C0037:2F or C003A:2F, Go to  AB3.
    For DTC C0030:07, C0033:07, C0036:07 or C0039:07, Go to  AB6.
  2. AB2: Check The Tires Size And Pressure 
    • Ignition OFF.
    • Verify all the tires and wheels are the same size and the tire size and inflation pressures are correct as indicated on the VC label.
    • Are the tires and wheels OK? 
    Yes No
    Go to  AB3. INSTALL the correct size tire or wheel or ADJUST tire pressure as necessary.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.
  3. AB3: Check The Wheel Speed Sensor Mounting 
    • With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to the Jacking and Lifting article.
    • Inspect the wheel speed sensor for correct installation and the fastener for looseness.
    • Make sure the electrical connector is fully seated and the locking tab (if present) is fully closed.
    • Is the wheel speed sensor installed correctly, the fastener tightened to specifications and the electrical connector fully seated and locked? 
    Yes No
    Go to  AB5. REINSTALL the wheel speed sensor and tighten the fastener to specifications. Make sure the electrical connector is fully seated and the locking tab (if present) is fully closed. REFER to the appropriate procedure in the Anti-Lock Brake System (ABS) and Stability Control article.
    Go to  AB4.
  4. AB4: Check The Wheel Speed Sensor Inputs 
    • Ignition ON, engine OFF.
    • Access the ABS and monitor the LF_WSPD (SPD) PID.
    • Access the ABS and monitor the RF_WSPD (SPD) PID.
    • Access the ABS and monitor the LR_WSPD (SPD) PID.
    • Access the ABS and monitor the RR_WSPD (SPD) PID.
    • Drive the vehicle at a speed greater than 20 km/h (12 mph) while monitoring the PIDs.
    • Are the wheel speed PIDs within 5 km/h (3 mph) of each other and the vehicle speed as indicated on the speedometer? 
    Yes No
    The system is operating correctly at this time. The concern may have been caused by a loose or incorrectly installed wheel speed sensor.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.    		 Go to  AB5.
  5. AB5: Check The Wheel Speed Sensor For Damage 
    • Ignition OFF.
    • With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to the Jacking and Lifting article.
    • Disconnect the suspect wheel speed sensor electrical connector.
    • Inspect the wheel speed sensor and harness for abrasions, broken connector tabs or water intrusion.
    • Are the wheel speed sensor and harness OK? 
    Yes No
    Go to  AB6. INSTALL a new WSS or harness as required.
    REFER to the Anti-Lock Brake System (ABS) and Stability Control article. DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.
  6. AB6: Check The Encoder For Damage 
  7. AB7: Check The Wheel Speed Sensor PIDs 
    • Ignition ON, engine OFF.
    • Access the ABS and monitor the LF_WSPD (SPD) PID.
    • Access the ABS and monitor the RF_WSPD (SPD) PID.
    • Access the ABS and monitor the LR_WSPD (SPD) PID.
    • Access the ABS and monitor the RR_WSPD (SPD) PID.
    • Drive the vehicle at a speed greater than 48 km/h (30 mph) while monitoring the PIDs.
    • Are the wheel speed PIDs within 5 km/h (3 mph) of each other and the vehicle speed as indicated on the speedometer? 
    Yes No
    Go to  AB8. CLEAN the space between the wheel speed sensor encoder ring and the wheel speed sensor. INSPECT the air gap. INSTALL a new wheel bearing, rear half-shaft or wheel speed sensor as necessary. REFER to the Front Suspension, Rear Suspension, Rear Drive Halfshafts or the Anti-Lock Brake System (ABS) and Stability Control article.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.
  8. AB8: Check For Correct ABS Module Output 
    • Put the ABS module in sleep mode by performing the following steps:
      • With ALL doors closed, set the ignition from ON to OFF.
      • Disconnect the diagnostic scan tool.
      • Open the door, exit the vehicle and close the door.
      • Wait a minimum of 90 seconds for the ABS module to enter sleep mode.
    • Disconnect the suspect wheel speed sensor electrical connector.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Left Front Wheel Speed Sensor (C150) Connector, Harness Side (-) Left Front Wheel Speed Sensor (C150) Connector, Harness Side
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 1 LF WSS LO - RCA17 - Pin 2
    • Measure the voltage between:
      (+) Right Front Wheel Speed Sensor (C160) Connector, Harness Side (-) Right Front Wheel Speed Sensor (C160) Connector, Harness Side
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 1 RF WSS LO - RCA19 - Pin 2
    • Measure the voltage between:
      (+) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side (-) Left Rear Wheel Speed Sensor (C440) Connector, Harness Side
      LR WSS HI - VCA04 (BLUE/ORANGE) - Pin 1 LR WSS LO - RCA18 - Pin 2
    • Measure the voltage between:
      (+) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side (-) Right Rear Wheel Speed Sensor (C426) Connector, Harness Side
      RR WSS HI - VCA06 (WHITE/ORANGE) - Pin 1 RR WSS LO - RCA20 - Pin 2
    • Is the voltage greater than 10 volts?
    Yes No
    INSTALL a new WSS.
    REFER to the Anti-Lock Brake System (ABS) and Stability Control article. DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.    		 If the Rotunda Wheel Speed Sensor Tester special tool is available, Go to  AB9.
    If the Rotunda Wheel Speed Sensor Tester special tool is NOT available, Go to  AB13.
  9. AB9: Check The ABS Module Output With The Special Tool 
    • Set the transmission to NEUTRAL and position the vehicle on a hoist. Refer to the Jacking and Lifting article.
    • Make sure the special tool power switch is in the OFF position.
    • Ignition OFF.
    • Disconnect the suspect wheel speed sensor.
    • Connect the special tool to the wheel speed sensor and vehicle harness.
    • Set the special tool power switch to the ON position.
    • Ignition ON, engine OFF.
    • Observe the Vehicle Module Output LED.
    • Is the Vehicle Module Output LED illuminated green? 
    Yes No
    Go to  AB10. REPAIR the circuit between the special tool and the ABS module.
  10. AB10: Check The Special Tool System Polarity 
    • Observe the Current Fault LED.
    • Is the Current Fault LED illuminated? 
    Yes No
    Go to  AB11. Go to  AB12.
  11. AB11: Recheck The Special Tool System Polarity 
    • Toggle the special tool system polarity switch from the current position to the other position.
    • Observe the Current Fault LED.
    • Is the Current Fault LED illuminated? 
    Yes No
    The wheel speed sensor is shorted internally. INSTALL a new wheel speed sensor. REFER to the Anti-Lock Brake System (ABS) and Stability Control article. Go to  AB12.
  12. AB12: Check The Wheel Speed Sensor 
    • Raise the vehicle on the hoist until the wheels can spin freely.
    • Slowly spin the suspect wheel while observing the High and Low Sensor Output LED s, the Current Fault LED and the Air Gap LED.
    • Do the High and Low Sensor Output LEDs illuminate and flash? 
    Yes No
    Go to  AB13. If neither of the High or Low LEDs illuminate,
    The wheel speed sensor is open internally. INSTALL a new wheel speed sensor. REFER to the Anti-Lock Brake System (ABS) and Stability Control article.
    If only one of the High or Low LEDs illuminates, The wheel speed sensor is stuck in one state.
    INSTALL a new wheel speed sensor. REFER to the Anti-Lock Brake System (ABS) and Stability Control article.
    If the Current Fault LED is red, The wheel speed sensor is shorted. INSTALL a new wheel speed sensor. REFER to the Anti-Lock Brake System (ABS) and Stability Control article.
    If the Air Gap LED is illuminated red, The wheel speed sensor is out of range from the encoder ring. CHECK for obstructions between wheel speed sensor and the encoder ring.
    If the Air Gap LED flashes, The wheel speed sensor is near the edge of the acceptable range. CHECK for obstructions between wheel speed sensor and the encoder ring.
  13. AB13: Verify All Wiring Connections 
    • Ignition OFF.
    • ABS_A Module connector disconnected. (C135A)
    • ABS_B Module connector disconnected. (C135B)
    • Disconnect the suspect wheel speed electrical connector.
    • If previously installed, disconnect the Rotunda Wheel Speed Sensor Tester special tool.
    • Using a good light source, inspect all disconnected electrical connectors for the following:
      • corrosion - install 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
    • Are the connectors free of corrosion, damaged pins, bent pins, pushed-out pins and spread terminals? 
  14. AB14: Check For Correct ABS Module Operation 
    • Connect the suspect wheel speed sensor. Make sure it seats and latches correctly.
    • ABS Module connector connected. Make sure the connector seats and latches correctly.
    • Operate the system and determine if the concern is still present.
    • Is the concern still present? 
    Yes No
    CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA.
    If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions.
    If no service articles address this concern, INSTALL a new ABS module. REFER to the Anti-Lock Brake System (ABS) and Stability Control article.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.    		 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.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.
  15. AB15: Check For Correct Abs Operation 
    • Connect the suspect wheel speed sensor. Make sure it seats and latches correctly.
    • ABS_A Module connector connected. (C135A) Make sure the connector seats and latches correctly.
    • ABS_B Module connector connected. (C135B) Make sure the connector seats and latches correctly.
    • Operate the system and determine if the concern is still present.
    • Is the concern still present? 
    Yes No
    CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA.
    If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions.
    If no service articles address this concern, INSTALL a new EBB unit (HCU and ABS module assembly). REFER to the Anti-Lock Brake System (ABS) and Stability Control article. DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.    		 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.
    DRIVE the vehicle at a speed greater than 20 km/h (12 mph) to clear the ABS module wheel speed sensor DTCs.
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