Toyota 4Runner: Master Cylinder Pressure Sensor Zero Point High Malfunction (C1422)

Toyota 4Runner Service Manual / Brake / Brake Control / Dynamic Control Systems / Vehicle Stability Control System(for Hydraulic Brake Booster) / Master Cylinder Pressure Sensor Zero Point High Malfunction (C1422)

DESCRIPTION

Refer to DTCs C1421, C1423 and C1424 (See page ).

DTC Code	DTC Detection Condition	Trouble Area
C1422	When the stop light switch assembly is off, the PM/C1 terminal voltage is 0.86 V or higher for 5 seconds or more.	Stop light switch assembly Stop light switch circuit Master cylinder pressure sensor circuit Master cylinder solenoid (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1380 (See page ).

CAUTION / NOTICE / HINT

NOTICE:

When replacing the master cylinder solenoid, perform calibration (See page ).

HINT:

When DTC C1425 is output together with DTC C1422, inspect and repair the trouble areas indicated by DTC C1425 first (See page ).

PROCEDURE

1.	CHECK STOP LIGHT OPERATION

(a) Check that the stop lights come on when the brake pedal is depressed and go off when the brake pedal is released.

OK:

Condition	Illumination Condition
Brake pedal depressed	On
Brake pedal released	Off

INSPECT STOP LIGHT CIRCUIT

2.	READ VALUE USING TECHSTREAM (STOP LIGHT SW)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Stop Light SW	Stop light switch assembly/ ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Stop Light SW

Stop light switch assembly/ ON or OFF

ON: Brake pedal depressed

OFF: Brake pedal released

(f) Check that the stop light condition observed on the Techstream changes according to brake pedal operation.

OK:

The Techstream displays ON or OFF according to brake pedal operation.

GO TO STEP 5

3.	CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION

(a) Turn the ignition switch off.

(b) Check the brake pedal height and stop light switch assembly installation (See page ).

OK:

The brake pedal height and stop light switch assembly installation are normal.

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH

4.	RECONFIRM DTC

(a) Clear the DTCs (See page ).

(b) Start the engine.

(c) Drive the vehicle at a speed of 40 km/h (25 mph) or more and perform a braking test (decelerate the vehicle by depressing the brake pedal).

(d) Check if the same DTC is output (See page
).

Result

Result	Proceed to
DTC C1422 is not output	A
DTC C1422 is output	B

USE SIMULATION METHOD TO CHECK

REPLACE MASTER CYLINDER SOLENOID

5.	CHECK TERMINAL VOLTAGE (STP)

REPLACE MASTER CYLINDER SOLENOID

REPAIR OR REPLACE HARNESS OR CONNECTOR

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