FixVault

Normal Operation and Fault Conditions

Active wheel speed sensors generate a square wave signal proportional to wheel speed which is sent to the ABS module. Each wheel speed sensor is connected to the ABS module through 2 wires and a connector at each wheel speed sensor. One wire is for sensor voltage supply from the ABS module and the other wire is for the signal return to the ABS module. When the ignition mode is set to ON, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry. 

Possible Causes 

Visual Inspection and Diagnostic Pre-checks 

NOTE: 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: Antilock Braking System (ABS) Module Connector - C135
G11681971Courtesy of FORD MOTOR CO.
CONNECTOR PIN REFERENCE (HARNESS SIDE)

Circuit Pin
LF WSS LO (Left Front Wheel Speed Sensor Low) - RCA17 8 (YELLOW)
LF WSS HI (Left Front Wheel Speed Sensor High) - VCA03 9 (VIOLET/WHITE)
RF WSS LO (Right Front Wheel Speed Sensor Low) - RCA19 4 (VIOLET)
RF WSS HI (Right Front Wheel Speed Sensor HI) - VCA05 5 (GRAY/VIOLET)
Fig 2: Left Front Wheel Speed Sensor Connector - C1315
G11681972Courtesy of FORD MOTOR CO.
CONNECTOR PIN REFERENCE (HARNESS SIDE)

Circuit Pin
LF WSS LO (Left Front Wheel Speed Sensor Low) - RCA17 2 (YELLOW)
LF WSS HI (Left Front Wheel Speed Sensor High) - VCA03 1 (VIOLET/WHITE)
Fig 3: Right Front Wheel Speed Sensor Connector - C1316
G11681973Courtesy of FORD MOTOR CO.
CONNECTOR PIN REFERENCE (HARNESS SIDE)

Circuit Pin
RF WSS LO (Right Front Wheel Speed Sensor Low) - RCA19 2 (VIOLET)
RF WSS HI (Right Front Wheel Speed Sensor HI) - VCA05 1 (GRAY/VIOLET)
  1. M1: CHECK FOR FAULT REPEATABILITY 
    • Ignition ON, engine OFF.
    • Clear the ABS DTCs.
    • Ignition OFF.
    • Ignition ON, engine OFF.
    • Test drive the vehicle above 20 km/h (12 mph).
    • Carry out the ABS self-test.
    • Is one or more of the DTCs shown in the ABS Module DTC Fault Trigger Conditions table present? 
      Yes No
      Go to  M2. The system is operating correctly at this time. INSPECT both front wheel speed sensor electrical connectors and the ABS module electrical connector. REPAIR or CLEAN the connector as necessary. ADDRESS the root cause of any connector or pin issues.
  2. M2: CHECK THE ABS MODULE DTCS 
    • Review the results from the ABS module self-test.
    • Is DTC C003x:01, C003x:12 or C003x:15 present? 
      Yes No
      Go to  M3. Go to  M4.
  3. M3: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO BATTERY VOLTAGE 
    • Ignition OFF.
      NOTE: The battery must be removed to access the ABS module electrical connector.
    • Remove the battery. REFER to Charging System (Battery, Battery Mounting And Battery Cables) .
    • ABS Module connector disconnected. (C135)
    • Disconnect the suspect wheel speed sensor.
    • Install the battery. REFER to Charging System (Battery, Battery Mounting And Battery Cables) .
    • Ignition ON, engine OFF.
    • For the left front wheel speed sensor:
    • Measure the voltage between:
      (+)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      (-)
      LF WSS LO - RCA17 (YELLOW) - Pin 2 Ground
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 1 Ground
    • For the right front wheel speed sensor:
    • Measure the voltage between:
      (+)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      (-)
      RF WSS LO - RCA19 (VIOLET) - Pin 2 Ground
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 1 Ground
    • Is any voltage present? 
      Yes No
      REPAIR the circuit. Go to  M4.
  4. M4: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • ABS Module connector disconnected. (C135) (if not previously disconnected)
    • Disconnect the suspect wheel speed sensor connector (if not previously disconnected).
    • For the left front wheel speed sensor:
    • Measure the resistance between:
      (+)
      ABS Module (C135) Connector, Harness Side
      (-)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      LF WSS LO - RCA17 (YELLOW) - Pin 8 LF WSS LO - RCA17 - Pin 2
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 9 LF WSS HI - VCA03 - Pin 1
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+)
      ABS Module (C135) Connector, Harness Side
      (-)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      RF WSS LO - RCA19 (VIOLET) - Pin 4 RF WSS LO - RCA19 - Pin 2
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 5 RF WSS HI - VCA05 - Pin 1
    • Are the resistances less than 3 ohms? 
      Yes No
      Go to  M5. REPAIR the circuit.
  5. M5: CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS 
    • Ignition OFF.
    • For the left front wheel speed sensor:
    • Measure the resistance between:
      (+)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      (-)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 1 LF WSS LO - RCA17 - Pin 2
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      (-)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 1 RF WSS LO - RCA19 - Pin 2
    • Is the resistance greater 10, 000 ohms? 
      Yes No
      Go to  M6. REPAIR the circuit.
  6. M6: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND 
    • For the left front wheel speed sensor:
    • Measure the resistance between:
      (+)
      ABS Module (C135) Connector, Harness Side
      (-)
      LF WSS LO - RCA17 (YELLOW) - Pin 8 Ground
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 9 Ground
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+)
      ABS Module (C135) Connector, Harness Side
      (-)
      RF WSS LO - RCA19 (VIOLET) - Pin 4 Ground
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 5 Ground
    • Are the resistances greater than 10, 000 ohms? 
      Yes No
      Go to  M7. REPAIR the circuit.
  7. M7: CHECK THE ABS MODULE OUTPUT 
    • Ignition ON, engine OFF.
    • For the left front wheel speed sensor:
    • Measure the voltage between:
      (+)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      (-)
      Left Front Wheel Speed Sensor (C1315) Connector, Harness Side
      LF WSS HI - VCA03 (VIOLET/WHITE) - Pin 1 LF WSS LO - RCA17 - Pin 2
    • For the right front wheel speed sensor:
    • Measure the voltage between:
      (+)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      (-)
      Right Front Wheel Speed Sensor (C1316) Connector, Harness Side
      RF WSS HI - VCA05 (GRAY/VIOLET) - Pin 1 RF WSS LO - RCA19 - Pin 2
    • Is the voltage greater 10 volts? 
      Yes No
      INSTALL a new wheel speed sensor. REFER to Anti-Lock Brake System (ABS) And Stability Control . Go to  M8.
  8. M8: VERIFY ALL WIRING CONNECTIONS 
    • Ignition OFF.
    • Disconnect all in-line electrical connectors between the ABS module and the suspect wheel speed sensor.
    • 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? 
      Yes No
      Go to  M9. REPAIR the affected connectors or terminals.
      REFER to OEM Connector Repair Procedures for schematic and connector information.
  9. M9: CHECK FOR CORRECT ABS MODULE OPERATION 
    NOTE: The battery must be removed to access the ABS module electrical connector.
    • Remove the battery. REFER to Charging System (Battery, Battery Mounting And Battery Cables) .
    • Connect all in-line electrical connectors between the ABS module and the suspect wheel speed sensor. Make sure the connectors seat and latch correctly.
    • Connect the suspect wheel speed sensor. Make sure the connector seats and latches correctly.
    • ABS Module connector connected. (C135) Make sure the connector seats and latches correctly.
    • Install the battery. REFER to Charging System (Battery, Battery Mounting And Battery Cables) .
    • Operate the system and determine if the concern is still present.
    • Is the concern still present? 
      Yes No
      INSTALL a new ABS module.
      CHECK OASIS for any applicable Technical Service Bulletins TSBs.
      If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions.
      If no TSBs address this concern, INSTALL a new ABS module.
      REFER to Anti-Lock Brake System (ABS) And Stability Control .
      ORDER a replacement ABS module and INCLUDE the RVC on the form.
      If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.
      When complete, SELECT the "X" in the top right corner to CLOSE this procedure.
      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.
      If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.
      When complete, SELECT the "X" in the top right corner to CLOSE this procedure.