DTC C1273 RF TCS Master Cylinder Isolation Valve Malfunction. Buick LeSabre 2000

For 1990-2009 cars only

Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1273 RF TCS Master Cylinder Isolation Valve Malfunction

DTC C1273 RF TCS Master Cylinder Isolation Valve Malfunction w/NW9

ABS Components
PWR, GND, Stoplamp Switch, Solenoid Valves, and Pump Motor
Handling ESD Sensitive Parts Notice

Circuit Description

The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve solenoids and the pump motor. This voltage is referred to as the system voltage. The electronic brake control module (EBCM) microprocessor activates the valve solenoids by grounding the control circuit.

Conditions for Running the DTC

•	The system voltage is greater than 8 volts.

•	The ignition voltage is greater than 9 volts.

Conditions for Setting the DTC

The commanded state of the driver and the actual state of the control circuit do not match for 0.03 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur:

•	The EBCM disables the ABS/TCS/VSES/DRP for the duration of the ignition cycle.

•	The ABS indicator turns ON.

•	The TRACTION OFF indicator turns ON.

•	The DIC displays the SERVICE STABILITY SYSTEM message.

•	DTC C1248 also sets.

•	The red BRAKE warning indicator turns ON.

Conditions for Clearing the DTC

•	The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

•	The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids

The solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM.