Pinpoint Test C: DTCs C1222, C1296, C1297, C1298 and C1299
Anti-Lock Control
Pinpoint Tests
Pinpoint Test C: DTCs C1222, C1296, C1297, C1298 and C1299
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The wheel speed sensor generates an analog signal that is proportional to wheel speed. The wheel speed sensor circuitry connects to the ABS module connector C135 through 2 wires and a connector at each wheel speed sensor. When the ignition is turned to the RUN position, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry to determine if they are functional. Power and ground are supplied to the wheel speed sensors from the ABS module.
The front wheel speed sensors are integral to the wheel hub and bearing assembly and have a serviceable jumper harness connecting the sensor to the main wire harness.
This pinpoint test is intended to diagnose the following:
- Front wheel speed sensor jumper harness
- Wheel speed sensor
- Wheel speed tone ring
- ABS module
PINPOINT TEST C: DTCs C1222, C1296, C1297, C1298 AND C1299
NOTICE: The Flex Probe Kit must be used for all test connections. Use of standard multi-meter probes may damage wiring terminals.
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C1 CHECK THE TIRES SIZE AND PRESSURE
- Verify that all tires and wheels are the same size and that the inflation pressures are correct as indicated on the Vehicle Identification Label (VIL).
- Are the wheels and tires OK?
Yes
GO to C2.
No
INSTALL the correct size tire or adjust tire pressure as necessary. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.
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C2 CHECK THE WHEEL SPEED SENSOR
- WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in Fire Suppression System. Failure to follow the instructions may result in serious personal injury Procedures.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- Check the suspect wheel speed sensor for correct mounting, excessive dirt build up, metal obstructions, incorrect harness routing and chafing.
- Is the suspect wheel speed sensor OK?
Yes
GO to C3.
No
For front wheel speed sensors, thoroughly inspect the front wheel speed sensor jumper harness. If the jumper harness is not OK, INSTALL a new jumper harness. If the jumper harness is OK, INSTALL a new front wheel speed sensor, REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front. For rear wheel speed sensors, INSTALL a new rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If equipped with a fire suppression system, GO to C8.
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C3 CHECK THE WHEEL SPEED SENSOR TONE RING
- Check the suspect wheel speed sensor tone ring for corrosion, nicks, damaged teeth, correct mounting, alignment and consistent air gap.
- Is the suspect wheel speed sensor tone ring OK?
Yes
GO to C4.
No
REPAIR or INSTALL a new wheel speed sensor ring. REFER to Front Suspension Front Suspension for front or Rear Drive Axle/Differential - Ford 8.8-Inch Ring Gear Service and Repair for rear. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If equipped with a fire suppression system, GO to C8.
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C4 CHECK THE WHEEL SPEED SENSOR OUTPUT
NOTE: To access the ABS module connector, remove the Air Cleaner (ACL) assembly.
- Ignition OFF.
- Disconnect: ABS Module C135.
- For DTC C1296 (LF), while spinning the suspect wheel at one revolution per second, measure the AC voltage between ABS module C135-22, circuit 521 (TN/OG), harness side and ABS module C135-21, circuit 522 (TN/BK), harness side.
- For DTC C1297 (RF), while spinning the suspect wheel at one revolution per second, measure the AC voltage between ABS module C135-6, circuit 514 (YE/RD), harness side and ABS module C135-18, circuit 516 (YE/BK), harness side.
- For DTC C1298 (RR), while spinning the suspect wheel at one revolution per second, measure the AC voltage between ABS module C135-31, circuit 523 (RD/PK), harness side and ABS module C135-19, circuit 524 (PK/BK), harness side.
- For DTC C1299 (LR), while spinning the suspect wheel at one revolution per second, measure the AC voltage between ABS module C135-20, circuit 518 (LG/RD), harness side ABS module C135-33, circuit 519 (LG/BK), harness side.
- Are the voltages between 100 and 3,500 millivolts AC?
Yes
GO to C7.
No
GO to C5.
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C5 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN
NOTE: To access the LH front wheel speed sensor electrical connector, remove the air cleaner assembly. To access the rear wheel speed sensors, remove the rear seat cushion.
- Disconnect: Suspect Wheel Speed Sensor.
- Measure the resistance between the ABS module connector, harness side and the suspect wheel speed sensor connector, harness side as indicated in the following chart:
- Are the resistances less than 5 ohms?
Yes
GO to C6.
No
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If equipped with a fire suppression system, GO to C8.
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C6 CHECK THE SUSPECT WHEEL SPEED SENSOR FOR A SHORT TO GROUND
- Measure the resistance between the suspect wheel speed sensor terminal and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to C7.
No
For front wheel speed sensors, thoroughly INSPECT the front wheel speed sensor jumper harness. If the jumper harness is not OK, INSTALL a new jumper harness. If the jumper harness is OK, INSTALL a new front wheel speed sensor, REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front. For rear wheel speed sensors, INSTALL a new rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If equipped with fire a suppression system, GO to C8.
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C7 CHECK FOR CORRECT ABS MODULE OPERATION
- Check ABS module connector C135 for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: ABS Module C135.
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module Service and Repair. TEST the system for normal operation. If equipped with a fire suppression system, GO to C8.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied. If equipped with a fire suppression system, GO to C8.
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C8 REPOWER THE FIRE SUPPRESSION SYSTEM
- WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System. Failure to follow these instructions may result in serious personal injury Description and Operation.
- Verify that the fire suppression system is repowered. Refer to Fire Suppression System Procedures.
- Is the fire suppression system repowered?
Yes
Fire suppression system repowering is complete.
No
REFER to Fire Suppression System Procedures for fire suppression system depowering and repowering procedure.
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