DTC C1273 RF TCS Master Cylinder Isolation Valve Malfunction. Chevrolet Corvette 1999

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1273 RF TCS Master Cylinder Isolation Valve Malfunction

Cell 44: Power and Ground
ABS Components
Antilock Brake System Schematic Icons

Circuit Description

The Master Cylinder Isolation valve solenoid circuits are supplied with battery power when the ignition is in the ON position. The EBTCM controls the valve functions by grounding the circuit when necessary.

Conditions 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

ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.

•	Indicators that turn on:

-	ABS indicator

-	Car Icon (TCS indicator)

•	Messages displayed on the DIC:

-	Service ABS

-	Service Traction System

-	Service Active HNDLG (if equipped with Active Handling RPO JL4)

Conditions for Clearing the DTC

•	Condition for DTC is no longer present and scan tool clear DTC function is used.

•	Fifty ignition cycles have passed with no DTCs detected.

Diagnostic Aids

Make sure the integrity of the connection between the EBTCM and the BPMV is secure, tight, and free from corrosion.

Test Description

The numbers below refer to step numbers on the diagnostic table.

Checks the resistance value of the solenoid.

Checks for a short to ground in the BPMV.

Checks for an internal short to voltage.

DTC C1273 Rear Master Cylinder Isolation Valve Malfunction

Step	Action	Value(s)	Yes	No
1	Was the Diagnostic System Check performed?	--	Go to Step 2	Go to Diagnostic System Check - ABS
2	Turn the ignition switch to the OFF position. Disconnect the EBTCM connector. Remove the EBTCM from the BPMV. Inspect the EBTCM to BPMV connector for conditions which could cause intermittents such as damage, corrosion, or poor terminal contact. Are internal connectors OK and cavity free of brake fluid?	--	Go to Step 3	Go to Step 6
3	Install J 41247 BPMV Pinout Box to the BPMV connector. Using J 39200 DMM, measure the resistance between J 41247 terminals 3 and 7. Is the resistance within the range specified in the value(s) column?	8-12 ohms	Go to Step 4	Go to Step 8
4	Using J 39200 DMM, measure the resistance between J 41247 terminal 3 and the BPMV case. Is the resistance within the range specified in the value(s) column?	OL (infinite)	Go to Step 5	Go to Step 8
5	Remove J 41247 . Reinstall the EBTCM to BPMV. Reconnect the EBTCM connector. Turn the ignition switch to the ON position, engine off. Does DTC C1273 reset as a current DTC?	--	Go to Step 9	Go to Step 7
6	If connector corrosion or damage are present, replace BPMV and/or EBTCM as necessary. If brake fluid is present, replace both the BPMV and EBTCM. Is the repair complete?	--	Go to Diagnostic System Check - ABS	--
7	Using a scan tool in ABS/TCS or ABS/TCS/Active Handling Special Functions run the AUTOMATED Test. Does DTC C1273 reset as a current DTC?	--	Go to Step 8	Go to Diagnostic System Check - ABS
8	Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement . Is the replacement complete?	--	Go to Diagnostic System Check - ABS	--
9	Replace the EBTCM. Refer to Electronic Brake Control Module Replacement . Is the replacement complete?	--	Go to Diagnostic System Check - ABS	--