C021

Part 1 Of 2:

Part 2 Of 2:

C0221 or C021

CIRCUIT DESCRIPTION
The wheel speed sensor coil emits an electromagnetic field. A toothed ring on the wheel passes by the wheel speed sensor and disrupts this electromagnetic field. The disruption in the field causes the wheel speed sensor to produce a sinusoidal (AC) voltage signal. The frequency and amplitude of the sinusoidal (AC) voltage signal are proportional to the speed of the wheel. The amplitude of the wheel speed signal is also directly related to the distance between the wheel speed sensor coil and the toothed ring. This distance is referred to as the air gap.

CONDITIONS FOR SETTING THE DTC
^ No output signal from the right front wheel speed sensor for 1.0 second
^ Excessive right front wheel speed sensor resistance for 1.0 second

ACTION TAKEN WHEN THE DTC SETS
^ The ABS indicator lamp turns on
^ The ABS disables

DTC C0221 is a Condition Latched Diagnostic Trouble Code (DTC), which indicates that the above actions remain true only as long as the condition persists.

CONDITIONS FOR CLEARING THE DTC
^ Repair the conditions responsible for setting the Diagnostic Trouble Code (DTC)
^ Use the Scan Tool Clear DTCs function

DIAGNOSTIC AIDS
Any of the following conditions may cause an intermittent malfunction:
^ A poor connection
^ Wire insulation that is rubbed through
^ A wire breaks inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal to wiring connections
^ Physical damage to the wiring harness

When inspecting a wheel speed sensor, inspect the sensor terminals and the harness connector for corrosion. If evidence of corrosion exists, then replace the wheel speed sensor. Refer to Wheel Speed Sensor Replacement.
Resistance of the wheel speed sensor will increase with an increase in sensor temperature. Refer to the ABS Diagnostic Specifications for temperature/resistance values.

TEST DESCRIPTION
The numbers below refer to the steps in the diagnostic table:
2. This step checks the resistance of the right front wheel speed sensor circuit.
3. This step checks for continuity in the right front wheel speed sensor harness.
4. This step checks the resistance of the right front wheel speed sensor.