C1274

Diagnostic Chart - Part 1 Of 4:

Diagnostic Chart - Part 2 Of 4:

Diagnostic Chart - Part 3 Of 4:

Diagnostic Chart - Part 4 Of 4:

Schematic Diagram:

CIRCUIT DESCRIPTION
The pressure switch monitors primary brake system pressure. The normally closed switch opens when the brakes are applied and pressure exceeds 700 kPa (101 psi). If the brakes are manually applied during traction control mode, the Brake Pressure Modulator Valve (BPMV) pressure switch input, along with the brake switch input, signal the Electronic Brake/Traction Control Module (EBCM/EBTCM) to disable traction control and allow manual braking. The pressure switch is part of the BPMV assembly and is not serviceable.

CONDITIONS FOR SETTING THE DTC
DTC C1274 sets when the EBTCM detects an open or short to ground in the BPMV pressure switch circuitry.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, TCS is disabled and the TRACTION OFF indicator lamp is turned ON.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and scan tool clear DTCs function is used.
^ 100 ignition switch key cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
Possible Causes:
- TCC/Antilock Switch circuit open or shorted to voltage.
- BPMV Fluid Level Switch circuit open or shorted to voltage.
- ABS Pump Motor Pressure Switch circuit open or shorted to voltage.

It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully inspect wiring may result in misdiagnosis, causing part replacement with reappearance of the malfunction.

DTC C1274 may also store along with DTC C1245. Diagnose DTC C1245 first before diagnosing DTC C1274.