C1235

Circuit Description
The wheel speed sensor generates an AC signal. The signal is produced when a toothed ring passes the wheel speed sensor. The frequency of the AC signal is proportional to the wheel speed. The EBCM uses the frequency of the signal in order to calculate the wheel speed.


Conditions for Running the DTC
The ignition is ON.


Conditions for Setting the DTC
- The voltage on the high and low circuits is greater than 4.25 volts
OR
^ The voltage on the high and low circuits is less than 0.75 volts
OR
^ The voltage on the high circuit is greater than 4.25 volts and the voltage on the low is less than 0.75 volts
Any of the above conditions are present for greater than 0.02 seconds


Action Taken When the DTC Sets
^ The EBCM disables the ABS
^ The ABS warning indicator turns ON.


Conditions for Clearing the DTC
^ The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
^ 100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition OFF.


Diagnostic Aids
The following conditions may cause an intermittent malfunction:
^ A poor connection
^ Rubbed-through wire insulation
^ A broken wire inside the insulation
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal-to-wiring connections
^ Physical damage to the wiring harness
Resistance of the wheel speed sensor will increase with an increase in sensor temperature.
Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids if an intermittent malfunction exists.


Test Description
The number below refers to the step number on the diagnostic table.
2. This step tests the wheel speed sensor and the wheel speed sensor signal circuits for an open.
3. This step tests the wheel speed sensor and the wheel speed sensor signal circuits for a short to ground.
4. This step tests the wheel speed sensor and the wheel speed sensor signal circuits for a short to voltage.
5. This step tests the wheel speed sensor for the proper resistance value.