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Visual Inspection and Diagnostic Pre-checks

WARNING: This page is about a different car, the 2018 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
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. 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 DTC Fault Trigger Conditions table present? 
    Yes No
    If DTC C1A95:01 is the only DTC present, Go to  M2.
    For failure type byte 11 (Circuit Short to Ground) or 14 (Circuit Short to Ground or Open Circuit), Go to  M4. For failure type byte 01 (General Electrical Failure), 12 (Circuit Short to Ground) or 15 (Circuit Short to Battery or Open Circuit), Go to  M3.    		 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: DETERMINE WHICH WHEEL SPEED SENSOR IS AT FAULT 
    • Test drive the vehicle while recording the wheel speed sensor PIDs.
    • 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.
    • Is a front wheel speed sensor at fault? 
    Yes No
    Go to  M3. Go to PINPOINT TEST N .
  3. M3: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO BATTERY VOLTAGE 
    • Ignition OFF.
    • ABS Module connector disconnected.
    • Disconnect the suspect wheel speed sensor.
    • Ignition ON, engine OFF.
    • For the left front wheel speed sensor:
    • Measure the voltage between:
      (+) Left Front Wheel Speed Sensor Sensor Connector, Harness Side (-)
      LF WSS LO Ground
      LF WSS HI Ground
    • For the right front wheel speed sensor:
    • Measure the voltage between:
      (+) Right Front Wheel Speed Sensor Connector, Harness Side (-)
      RF WSS LO Ground
      RF WSS HI Ground
    • Is any voltage present? 
    Yes No
    REPAIR the circuit. Go to  M4.
  4. M4: CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND 
    • Ignition OFF.
    • ABS Module connector disconnected. (if not previously disconnected)
    • Disconnect the suspect wheel speed sensor (if not previously disconnected).
    • For the left front wheel speed sensor:
    • Measure the resistance between:
      (+) ABS Module Connector, Harness Side (-)
      LF WSS LO Ground
      LF WSS HI Ground
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+) ABS Module Connector, Harness Side (-)
      RF WSS LO Ground
      RF WSS HI Ground
    • Are the resistances greater than 10, 000 ohms? 
    Yes No
    Go to  M5. REPAIR the circuit.
  5. M5: CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS 
    • For the left front wheel speed sensor:
    • Measure the resistance 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
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+) Right Front Wheel Speed Sensor Connector, Harness Side (-) Right Front Wheel Speed Sensor Connector, Harness Side
      RF WSS HI RF WSS LO
    • Is the resistance greater 10, 000 ohms? 
    Yes No
    Go to  M6. REPAIR the circuit.
  6. M6: CHECK THE WHEEL SPEED CIRCUITS FOR AN OPEN 
    • For the left front wheel speed sensor:
    • Measure the resistance between:
      (+) ABS Module Connector, Harness Side (-) Left Front Wheel Speed Sensor Sensor Connector, Harness Side
      LF WSS LO LF WSS LO
      LF WSS HI LF WSS HI
    • For the right front wheel speed sensor:
    • Measure the resistance between:
      (+) ABS Module Connector, Harness Side (-) Right Front Wheel Speed Sensor Connector, Harness Side
      RF WSS LO RF WSS LO
      RF WSS HI RF WSS HI
    • Are the resistances less than 3 ohms? 
    Yes No
    Go to  M7. REPAIR the circuit.
  7. M7: CHECK THE ABS MODULE OUTPUT 
    • ABS Module connector connected.
    • Ignition ON, engine OFF.
    • For the left front wheel speed sensor:
    • 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
    • For the right front wheel speed sensor:
    • 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
    • Is the voltage greater 11 volts? 
    Yes No
    INSTALL a new WSS.
    REFER to REMOVAL AND INSTALLATION    		 Go to  M8.
  8. M8: VERIFY ALL WIRING CONNECTIONS 
    • Ignition OFF.
    • ABS Module connector disconnected.
    • 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 (EXCEPT ELECTRIC) for schematic and connector information.
  9. M9: CHECK FOR CORRECT ABS MODULE OPERATION 
    • ABS Module connector connected. Make sure the connector seats and latches correctly.
    • Connect the suspect wheel speed sensor electrical connector. 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.
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