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Possible Causes

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector
  1. AB1: CHECK FOR ABS MODULE DTCS 
    • 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, C0031:2F, C0034:2F, C0034:07, C0037:07 C0037:2F, C0039:2F or C0039:0A, Go to  AB3.
    For DTC C0030:07, C0033:07, C0036:07 or C0039:07, Go to  AB5.
  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.
  3. AB3: CHECK THE WHEEL SPEED SENSOR MOUNTING 
    • With the transmission in NEUTRAL, position the vehicle on a hoist. Refer to JACKING AND LIFTING - OVERVIEW
    • Inspect the wheel speed sensor for correct installation and the fastener for looseness.
    • Is the wheel speed sensor installed correctly and the fastener tightened to specifications? 
    Yes No
    Go to  AB5. REINSTALL the wheel speed sensor and tighten the fastener to specifications. REFER to the appropriate REMOVAL AND INSTALLATION procedure. 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. 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 JACKING AND LIFTING - OVERVIEW
    • Disconnect the suspect wheel speed sensor electrical connector.
    • Inspect the wheel speed sensor and harness for abrasions, broken connector tabs or water intrusion.
    • Is the wheel speed sensor and harness OK? 
    Yes No
    For Escape/Kuga with AWD, Go to  AB8.
    For MKC with AWD, Go to  AB8.
    For Ka, Go to  AB7.
    For all others, Go to  AB6.    		 INSTALL a new wheel speed sensor. REFER to the appropriate procedure in REMOVAL AND INSTALLATION .
  6. AB6: CHECK WHEEL BEARING AND ENCODER FOR DAMAGE 
    • Inspect the wheel bearings for abnormal wear or roughness and for deformation or contamination of the seal and encoder.
    • Is the wheel bearing and encoder OK? 
    Yes No
    Go to  AB9. INSTALL a new wheel bearing as necessary. REFER to the appropriate article.
  7. AB7: CHECK FRONT HALFSHAFT CV JOINT ENCODER AND REAR WHEEL BEARING ENCODER FOR DAMAGE 
    NOTE: It may be necessary to remove the rear wheel speed sensor or rear wheel bearing and wheel hub to thoroughly inspect the encoder.
    • Inspect the front halfshaft CV joint for damage, a torn boot, and for deformation or contamination of the wheel speed sensor encoder ring.
    • Inspect the rear wheel bearings for abnormal wear or roughness and for deformation or contamination of the seal and encoder.
    • Are the CV joints, wheel bearings and encoders OK? 
    Yes No
    Go to  AB9. INSTALL a new front wheel bearing and wheel hub assembly or rear halfshaft as necessary. REFER to the appropriate article
  8. AB8: CHECK REAR HALFSHAFT CV JOINT AND FRONT WHEEL BEARING AND ENCODER FOR DAMAGE 
    NOTE: It may be necessary to remove the rear wheel speed sensor or rear wheel bearing and wheel hub to thoroughly inspect the encoder.
    • Inspect the rear halfshaft CV joint for damage, a torn boot, and for deformation or contamination of the encoder.
    • Inspect the front wheel bearings for abnormal wear or roughness and for deformation or contamination of the seal and encoder.
    • Are the CV joints, wheel bearings and encoders OK? 
    Yes No
    Go to  AB9. INSTALL a new front wheel bearing and wheel hub assembly or rear halfshaft as necessary. REFER to the appropriate article
  9. AB9: CHECK FOR CORRECT ABS MODULE OUTPUT 
    • Ignition OFF.
    • Disconnect the suspect wheel speed sensor electrical connector.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) Left Front Wheel Speed Sensor Sensor Connector, Harness Side (-) Left Front Wheel Speed Sensor Sensor Connector, Harness Side
      LF WSS HI LF WSS LO
    • Measure the voltage between:
      (+) Right Front Wheel Speed Sensor Connector, Harness Side (-) Right Front Wheel Speed Sensor Connector, Harness Side
      RF WSS HI RF WSS LO
    • Measure the voltage between:
      (+) Left Rear Wheel Speed Sensor Connector, Harness Side (-) Left Rear Wheel Speed Sensor Connector, Harness Side
      LR WSS HI LR WSS LO
    • Measure the voltage between:
      (+) Right Rear Wheel Speed Sensor Connector, Harness Side (-) Right Rear Wheel Speed Sensor Connector, Harness Side
      RR WSS HI RR WSS LO
    • Is the voltage greater than 10 volts? 
    Yes No
    INSTALL a new wheel speed sensor. REFER to the appropriate procedure in REMOVAL AND INSTALLATION . Go to  AB10.
  10. AB10: VERIFY ALL WIRING CONNECTIONS 
    • Ignition OFF.
    • ABS Module connector disconnected.
    • Disconnect the suspect wheel speed electrical connector.
    • 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  AB11. REPAIR the connector or terminals. Refer to OEM CONNECTOR REPAIR PROCEDURES (EXCEPT ELECTRIC) , for schematic and connector information.
  11. AB11: 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
    INSTALL a new ABS module.
    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 ANTI-LOCK BRAKE SYSTEM (ABS) MODULE
    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.    		 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.
  12. AB12: CHECK FOR CORRECT ABS 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.
    • Install the battery. Refer to the appropriate procedure in CHARGING SYSTEM (BATTERY, MOUNTING AND CABLES) (EXCEPT ELECTRIC) .
    • 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 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 and HCU assembly. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE
    ORDER a replacement ABS module and HCU assembly. INCLUDE the RVC form.
    If this is a Ford paid repair, INCLUDE the RVC on the warranty claim form.    		 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.
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