Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C1120 00: Left Front Brake Hydraulic Circuit BlockedDTC C1121 00: Left Front Brake Hydraulic Circuit Leaking
Circuit/System Description
The electronic brake control module EBCM) activates the valve relay to supply voltage to the valve solenoids. This voltage is referred to as the system voltage. The EBCM activates individual valve solenoids by grounding the valve solenoid control circuits.
Conditions for Running the DTC
| • | Ignition ON. |
| • | The ignition voltage is greater than 10 volts. |
Conditions for Setting the DTC
C1120 00
The EBCM is commanding a valve solenoid to release brake pressure. The wheel that is commanded to release brake pressure has a speed less than 5 km/h (3 mph) for 1.25 seconds.
C1121 00
The pressure change of the accumulator indicates the volume of fluid used which is compared to expected fluid used during a brake apply. Too much fluid usage indicates a leaking circuit
Action Taken When the DTC Sets
| • | The EBCM disables the antilock brake system (ABS), traction control and the vehicle stability enhancement system (VSES) for the duration of the ignition cycle. |
| • | A DIC message and/or a warning indicator may be displayed. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles. |
Reference Information
Schematic Reference
Antilock Brake System Schematics
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, verify that DTC C1120 or C1121 are not set.
| ⇒ | If the DTC is set, replace the brake pressure modulator valve. If the DTC resets, replace the EBCM.. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for EBCM replacement, setup, and programming |
