GM Service Manual Online
For 1990-2009 cars only

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 Descriptor

DTC C1225: SM Solenoid Circuit Malfunction

Circuit/System Description

The solenoid valves are part of the brake pressure modulator valve (BPMV). The BPMV turns ON and OFF the solenoid valves as deemed necessary to modulate hydraulic pressure to the wheel brakes.

Conditions for Running the DTC

Ignition voltage is greater than 9.5 volts.

Conditions for Setting the DTC

The electronic brake control module (EBCM) detects one of the following conditions in the solenoid circuitry:

    • An open
    • A short to ground
    • A short to voltage

Action Taken When the DTC Sets

    • The ABS is disabled.
    • The ABS warning indicator turns ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

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

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, verify that DTC C1225 is not set.

If DTC is set, replace the EBCM/BPMV.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake Pressure Modulator Valve Replacement
    •  Control Module References for EBCM replacement, setup, and programming