C1273
DTC C0200-C0215, C1235-C1239, or C1271-C1278
Circuit Description
As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
* DTC C0200 Right Front Wheel Speed Sensor Circuit
* DTC C0205 Left Front Wheel Speed Sensor Circuit
* DTC C0210 Right Rear Wheel Speed Sensor Circuit
* DTC C0215 Left Rear Wheel Speed Sensor Circuit
* DTC C1235 Right Front Wheel Speed Sensor Circuit Open
* DTC C1236 Left Front Wheel Speed Sensor Circuit Open
* DTC C1238 Right Rear Wheel Speed Sensor Circuit Open
* DTC C1239 Left Rear Wheel Speed Sensor Circuit Open
* DTC C1271 Right Front Wheel Speed Sensor Circuit Low
* DTC C1272 Left Front Wheel Speed Sensor Circuit Low
* DTC C1273 Right Rear Wheel Speed Sensor Circuit Low
* DTC C1274 Left Rear Front Wheel Speed Sensor Circuit Low
* DTC C1275 Right Front Wheel Speed Range Performance
* DTC C1276 Left Front Wheel Speed Range Performance
* DTC C1277 Right Rear Wheel Speed Range Performance
* DTC C1278 Left Rear Wheel Speed Range Performance
Conditions for Running the DTC
C0200, C0205, C0210, and C0215
The ignition is in the ON position.
C1235, C1236, C1238, and C1239
* The ignition is in the ON position.
* Vehicle speed of 20 km/h (12 mph) or more
C1271, C1272, C1273, and C1274
* The ignition is in the ON position.
* Vehicle speed of 20 km/h (12 mph) or more
C1275, C1276, C1277, and C1278
* The ignition is in the ON position.
* Vehicle speed of 20 km/h (12 mph) or more
Conditions for Setting the DTC
C0200, C0205, C0210, and C0215
The EBCM detects one of the following conditions in the wheel speed sensor circuits:
* An open
* A short to ground
* A short to voltage
C1235, C1236, C1238, and C1239
The EBCM detects noise in the wheel speed sensor signal for more than 5 seconds.
C1271, C1272, C1273, and C1274
The EBCM detects low output voltage of the wheel speed sensor.
C1275, C1276, C1277, and C1278
The EBCM detects a rapid change in the wheel speed which is determined to be unreasonable.
Action Taken When the DTC Sets
The following actions occur:
* The EBCM disables the antilock brake system (ABS) for the duration of the ignition cycle.
* The ABS indicator turns ON.
Conditions for Clearing the DTC
C0205, C0210, C0215, and C0220
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
C1235, C1236, C1238, and C1239
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
C1271, C1272, C1273, and C1274
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
C1275, C1276, C1277, and C1278
* The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
* After the DTC is cleared, the ABS indicator will remain ON until the vehicle is road tested to verify the repair. Once the vehicle has been driven at a speed above 16 km/h (10 mph) for 20 seconds with no malfunctions present, the EBCM will turn OFF the ABS indicator.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
* A short to ground or a short to voltage in the wheel speed sensor circuitry
* An open or high resistance in the wheel speed sensor circuitry
* A malfunctioning wheel speed sensor
* A malfunctioning wheel speed sensor rotor
* An internal EBCM malfunction
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics
Test Description
The number below refers to the step number on the diagnostic table.
3. This step tests the wheel speed sensor for the proper resistance value.
Step 1 - Step 7:
Step 8 - Step 13:
