C0269

Circuit Description
C0269
The EBCM commands the dump valve solenoid on in order to open the dump valve and decrease the hydraulic pressure in a brake circuit.
C0274
The EBCM commands the isolation valve solenoid on in order to close the isolation valve and prevent the application of additional hydraulic pressure to a brake circuit.

Conditions for Running the DTC
^ The ignition is ON.
^ The vehicle is experiencing an ABS event.

Conditions for Setting the DTC
C0269
The EBCM microprocessor commands one or more dump valve solenoids on for 9 consecutive seconds.
C0274
The EBCM microprocessor commands one or more isolation valve solenoids on for 255 consecutive seconds.

Action Taken When the DTC Sets
C0269
^ The ABS and TRACTION OFF (if equipped with Traction Control) indicators are commanded on.
^ The Traction Control (if equipped) is disabled for the remainder of the ignition cycle.
^ If the dump command is directed to a front wheel, the front ABS is disabled for the remainder of the ignition cycle.
^ If the dump command is directed to the rear wheels, the ABS and DRP are disabled for the remainder of the ignition cycle. In this situation, the BRAKE indicator is also commanded on.
C0274
^ The ABS and BRAKE indicators are commanded on.
^ The ABS and DRP are disabled for the remainder of the ignition cycle.

Conditions for Clearing the DTC
^ The condition(s) responsible for setting the DTC are no longer present.
^ A scan too] is used in order to clear the DTC.

Diagnostic Aids
The most likely cause of DTC C0269 or DTC C0274 is a mechanical failure that causes a wheel to lock and remain locked. The DTC(s) may also set, conceivably, when the ABS is activated on surfaces that are nearly impossible to get traction on (i.e.; sheet ice). If the DTC sets within these conditions, diagnosis of the ABS system is not necessary.

Test Description
The number below refers to the step number on the diagnostic table.
2. Using the scan tool to perform solenoid tests determines if there is a mechanical malfunction(s) inside the BPMV (i.e.; a dump valve(s) stuck closed or an isolation valve(s) stuck open). Perform Dump Valve Tests for DTC C0269 or Isolation Valve Tests for DTC C0274.