DTC 73

This article has been updated with Bulletin No.: 63-50-11

RF TCS Master Cylinder Isolation Valve Malfunction:

CIRCUIT DESCRIPTION
The master cylinder isolation valve solenoid circuit is supplied with battery power when the ignition is in the "RUN" position. The EBTCM controls the valve by grounding the circuit when necessary.

DTC WILL SET WHEN
The EBTCM senses a discrepancy such as an open, short to ground. or short to voltage in the circuit.

ACTION TAKEN
A malfunction DTC is stored, ABS/TCS is disabled and the "ANTILOCK" and "TRACTION OFF" indicator lamps are turned "ON."

DTC CHART TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the diagnostic chart.
1. Checks condition of EBCM/EBTCM to BPMV connector and for presence of brake fluid in the EBCM/EBTCM.
2. Checks the integrity of the affected valve solenoid circuitry internal to the BPMV, and the valve solenoid coil.
3. Checks for solenoid circuit short to ground (BPMV case).
4. Checks for continued DTC setting after validating that the circuitry and the solenoid valves are good. If DTC resets, the EBCM/EBTCM is likely malfunctioning.

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.