C0237

Circuit Description
The EBCM receives the rear wheel speed signal from the Powertrain Control Module (PCM) (2.2L). The rear wheel speed signal originates from the Vehicle Speed Sensor (VSS) which is connected to the PCM. When the vehicle is not moving, the PCM will have 12 VDC present on the circuit. The EBCM checks for this voltage when the vehicle is not moving.

Conditions for Running the DTC
- Ignition switch in the RUN position.
- All wheel speed sensor signals above 32 km/h (20 mph) with brake applied, or 19 km/h (12 mph) with brake released.

Conditions for Setting the DTC
- Sudden loss of front wheel speed sensor signal 10 to 15 milliseconds.
- Sudden increase in rear wheel speed sensor signal for 105 milliseconds.

Action Taken When the DTC Sets
- The ABS indicator lamp turns on
- The ABS disables
Malfunction responses to DTC C0237 vary, depending on the affected subsystem.
- ABS-Condition latched
- DRP-DRP critical
For a detailed explanation of DTC malfunction responses, refer to: Self-Diagnostics.

Conditions for Clearing the DTC
- Repair the conditions responsible for setting the DTC.
- Use the Clear DTCs function on the Scan Tool
- Both a Condition Latched or Ignition Latched DTC may exist momentarily, or constantly. In either of the cases, the DTC will be stored in the EBCM memory until it is repaired, and/or the DTC is cleared. After the DTC is repaired and/or cleared and the ignition is turned to ON, the ABS lamp will remain lit until the EBCM completes a power-up self test. This test concludes when the vehicle has reached a speed of greater than 13 km/h (8 mph) and the wheel speed inputs have been checked by the EBCM.

Diagnostic Aids
Check for and clear DTCs in the PCM first.
This DTC can be set by a malfunction in the VSS, or a fault in CKT 821, 822 or 1827.
In addition, 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

Test Description
The numbers below refer to the steps in the diagnostic chart:
[3] This step uses the voltage output from the PCM to check the CKT 1827.
[4] This step attempts to determine if there the PCM can process the VSS input and deliver a VSS output on CKT 1827.

Steps 1-3:

Steps 4-8:

Step 9:

Diagnostic Chart