Diagnostic Instructions
DTC Descriptor
DTC C0137 11: Base Brake System Pressure Circuit Range Above Maximum
DTC C0137 12: Base Brake System Pressure Circuit Range Below Maximum Threshold
Circuit/System Description
The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor for more accurate braking control when the vehicle stability enhancement system (VSES) is active.
Conditions for Running the DTC
| • | Ignition voltage is greater than 8 volts. |
Conditions for Setting the DTC
The brake fluid pressure is less than 345 kPa (50 psi) for 3 deceleration cycles.
Action Taken When the DTC Sets
| • | The EBCM disables the VSES for the duration of the ignition cycle. |
| • | The traction control off indicator illuminates. |
| • | The driver information center (DIC) displays the TRAC/STABILITRAK OFF message. |
| • | The antilock brake system (ABS) remains functional. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
| • | Find out from the driver under what conditions the DTC was set. This information will help to duplicate the failure. |
| • | The Snapshot function on the scan tool can help find an intermittent DTC. |
| • | A deceleration cycle consists of the following sequence: |
| 1. | The vehicle speed is greater than 24 km/h (15 mph). |
| 2. | The vehicle decelerates more than 8 km/h/second (5 mph/second) for 2 seconds. |
| 3. | The vehicle speed decelerates to less than 16 km/h (10 mph). |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
ABS Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for Scan Tool Information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the brake fluid pressure sensor.
- Test for less than 2.0 ohms between the low reference circuit terminal 1 and ground.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the EBCM. |
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the EBCM. |
- Verify the scan tool Brake Fluid Pressure Sensor is less than 0.2 volt.
| ⇒ | If greater than the specified range, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the EBCM. |
- Install a 3A fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 3. Verify the scan tool Brake Pressure Sensor Input is greater than 4.7 volts.
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EBCM. |
- If all circuits test normal, test or replace the brake fluid pressure sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Control Module References
for EBCM replacement, setup, and programming
