Vehicle Stability Control System

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1254/54: Pressure Switch Circuit

DTC C1254/54 - Pressure Switch Circuit

DESCRIPTION





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (PRESSURE SWITCH (PH AND PL))
(a) Check the Data List for proper functioning of the hydraulic brake booster pressure switch (PH and PL).
(1) Depress the brake pedal more than 40 times with the ignition switch OFF, and then turn the ignition switch ON and check the pressure switch (PH and PL) condition.

ABS/VSC/TRAC





HINT: When pressure in the power supply system is released, the brake pedal becomes easier to depress.

OK:
"OFF" turns to "ON".
OK -- REPLACE SKID CONTROL ECU
NG -- Continue to next step.
2. CHECK BRAKE BOOSTER PRESSURE SWITCH (PH)




(a) Disconnect the B1 connector from the brake actuator.
(b) With the ignition switch OFF, depress the brake pedal more than 40 times to decrease the accumulator pressure.
HINT: When pressure in the power supply system is released, the brake pedal becomes easier to depress.
(c) Measure the resistance between terminals PH and PHG of the brake actuator connector.
Standard resistance:
0.9 to 1.1 kOhms
(d) Connect the B1 connector to the brake actuator.
(e) Disconnect the B1 connector after the ignition switch has been ON and the pump motor has stopped.
(f) Measure the resistance between terminals PH and PHG of the brake actuator.
Standard resistance:
0 Ohms
HINT: After the inspection, connect the connector and clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NG -- REPLACE BRAKE ACTUATOR
OK -- Continue to next step.
3. CHECK BRAKE BOOSTER PRESSURE SWITCH (PL)




(a) Disconnect the B2 connector from the brake actuator.
(b) With the ignition switch OFF, depress the brake pedal more than 40 times to decrease the accumulator pressure.
HINT: When pressure in the power supply system is released, the brake pedal becomes easier to depress.
(c) Measure the resistance between terminals PL and PLG of the brake actuator connector.
Standard resistance:
5.1 to 6.3 kOhms
(d) Connect the B2 connector to the brake actuator.
(e) Disconnect the B2 connector after the ignition switch has been ON and the pump motor has stopped.
(f) Measure the resistance between terminals PL and PLG of the brake actuator.
Standard resistance:
1.0 kOhms
HINT: After the inspection, connect the connector and clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NG -- REPLACE BRAKE ACTUATOR
OK -- Continue to next step.
4. CHECK WIRE HARNESS (BRAKE ACTUATOR - SKID CONTROL ECU AND BODY GROUND)




(a) Disconnect the B1 and B2 actuator connectors.
(b) Disconnect the S5 and S8 ECU connectors.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- REPLACE SKID CONTROL ECU