C1222

DTC C1222: Right Front Wheel Speed Sensor Input Signal = 0 (Part 1 Of 2):

DTC C1222: Right Front Wheel Speed Sensor Input Signal = 0 (Part 2 Of 2):

DTC C1222 Schematic:

Circuit Description
As a toothed ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor to produce a small AC voltage signal whose frequency is proportional to wheel speed.

Conditions for Setting the DTC
This DTC will set when the following conditions are met:
^ Right front wheel speed is equal to zero for greater than 1.6 seconds while the other two wheel speeds are greater than 8 km/h (5 mph) and within 11 km/h (7 mph).
^ This DTC can be set when the vehicle is not in an ABS stop.

Action Taken When the DTC Sets
A malfunction DTC is stored, ABS is disabled, and the amber ABS indicator lamp is turned ON.

Conditions for Clearing the DTC
^ Conditions for the malfunction are no longer present and the Tech 2 scan tool Clear DTC Information function is used.
^ One hundred drive cycles have passed with no malfunctions detected.

Diagnostic Aids
The following list contains items that need to be inspected when diagnosing this system:
^ Wheel speed sensor physically damaged.
^ Wheel speed sensor input circuits shorted together.
^ Missing speed sensor ring.
^ Excessive wheel speed sensor gap.
Two separate wheel speed=0 DTCs will be set if two wheel speeds are 0 km/h (0 mph) for greater than 20 seconds while the remaining wheel speed(s) are greater than 16 km/h (10 mph) and within 11 km/h (7 mph).

An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. The frequency of the malfunction can be checked by using the Enhanced Diagnostic function of the Tech 2 scan tool, as described in Enhanced Diagnostics.

NOTE: Resistance of the wheel speed sensor will increase with an increase in sensor temperature.

When measuring for a short to ground in a wheel speed sensor wiring circuit, manually switch the J 39200 (Digital Multimeter) to the Meg-Ohms range. This will ensure a high resistance short to ground can be found. See J 39200 owners manual. When replacing a wheel speed sensor, inspect the sensor terminals and jumper harness connector for corrosion and/or water intrusion. If evidence of corrosion or water intrusion exists, replace both the wheel speed sensor and the jumper harness.



Test Description
The numbers below refer to step numbers on the diagnostic table.
5. Checks wheel speed sensor resistance.
6. Checks for voltage output from wheel speed sensor.
7. Ensures that the wheel speed sensor wires are not shorted together.
11. Checks if this DTC resets after a drive cycle.
12. Checks the wheel speed sensor output compared to the other two.