ABS - Integrated Chassis Control

DTC C1271: LF TCS Master Cylinder Isolation Valve Malfunction:

DTC C1271 Schematic:

CIRCUIT DESCRIPTION
The Release valve solenoid circuits are supplied with battery power when the ignition is in the RUN position. The EBTCM controls the valve functions by grounding the circuit when necessary.

CONDITION FOR SETTING THE DTC
The EBTCM senses a discrepancy such as an open, short to ground, or short to voltage in the circuit.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS/TCS/ICCS is disabled and the ABS and TRACTION CONTROL Indicator lamps are turned ON. Vehicles with ICCS2 will display the STABILITY REDUCED message on the DTC.

CONDITIONS FOR CLEARING THE DTC
Condition for DTC is no longer present and scan tool clear DTC function is used. Fifty start cycles have passed with no DTCs detected.

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

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
3. Checks the resistance value of the RR REL Valve Solenoid.
4. Checks for a short to ground in the BPMV.