Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Master Cylinder Pressure Sensor Zero Point High Malfunction (C1422)

DESCRIPTION

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1422

Master Cylinder Pressure Sensor Zero Point High Malfunction

When vehicle speed is 3 km/h (2 mph) or more and stop light switch assembly is OFF, master cylinder pressure continuously exceeds 1.764 MPa (18.0 kgf/cm2, 255 psi) for 5 seconds or more.

  • STOP fuse
  • Stop light switch assembly
  • Wire harness or connector
  • Skid control ECU (Brake actuator assembly)
  • Brake actuator assembly (Master cylinder pressure sensor)

WIRING DIAGRAM

Refer to DTC C1380 (See page CAUTION / NOTICE / HINT ).

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information (See page ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1.

CHECK DTC

(a) Clear the DTCs (See page ). (b) Turn the ignition switch off. ).

(b) Turn the ignition switch off.

(c) Start the engine.

(d) Perform a road test.

(e) Check for DTCs (See page ). Result ).

Result

Result

Proceed to

DTC C1422 is output

A

DTCs C1422 and C1380 are output

B

DTCs C1422 and C1425 are output

C

B

GO TO DIAGNOSTIC TROUBLE CODE CHART

C

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

2.

READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

(e) In accordance with the display on the Techstream, read the Data List.

ABS/VSC/TRAC

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Stop Light SW

Stop light switch assembly

ON or OFF

OFF: Brake pedal released

ON: Brake pedal depressed

-

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

OK:

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

NG

GO TO STEP 5

OK

3.

READ VALUE USING TECHSTREAM (MASTER CYLINDER PRESSURE SENSOR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

(e) In accordance with the display on the Techstream, read the Data List.

ABS/VSC/TRAC

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Master Cylinder Pressure

Master cylinder pressure sensor pressure

Min.: 0.00 MPa

Max.: 23.28 MPa

Brake pedal operated: Proportional to pedal force Brake

Brake pedal released: 0.00 to 1.76 MPa

-

OK:

Data List pressure is within standard range.

NG

REPLACE BRAKE ACTUATOR ASSEMBLY

OK

4.

RECONFIRM DTC

(a) Clear the DTCs (See page ). (b) Turn the ignition switch off. ).

(b) Turn the ignition switch off.

(c) Start the engine.

(d) Perform a road test.

(e) Check if the same DTC is recorded (See page Result Result ).

Result

Result

Proceed to

DTC C1422 is not output

A

DTC C1422 is output

B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE ACTUATOR ASSEMBLY

5.

CHECK BRAKE PEDAL AND STOP LIGHT SWITCH ASSEMBLY INSTALLATION

(a) Turn the ignition switch off.

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

OK:

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

NG

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY

OK

6.

INSPECT STOP LIGHT SWITCH ASSEMBLY

(a) Remove the stop light switch assembly (See page (b) Inspect the stop light switch assembly (See page ).

(b) Inspect the stop light switch assembly (See page OK: ).

OK:

The stop light switch assembly is normal.

NG

REPLACE STOP LIGHT SWITCH ASSEMBLY

OK

7.

CHECK HARNESS AND CONNECTOR (STP TERMINAL)

(a) Turn the ignition switch off.

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

(c) Disconnect the skid control ECU (brake actuator assembly) connector.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

S1-35 (STP) - Body ground

Stop light switch assembly on (Brake pedal depressed)

8 to 14 V

Stop light switch assembly off (Brake pedal released)

Below 1.5 V

Text in Illustration

*a

Front view of wire harness connector

(to Skid Control ECU [Brake Actuator Assembly])

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)

Open or Short in Master Cylinder Pressure Sensor (C1421,C1423,C1424,C142A,C1449)
DESCRIPTION DTC No. Detection Item DTC Detection Condition Trouble Area C1421 Open or Short in Master Cylinder Pressure Sensor ...

Open in Stop Light Switch Circuit (C1425)
DESCRIPTION The skid control ECU (brake actuator assembly) detects the brake operating conditions through a signal transmitted by the stop light switch. The skid control ECU incorporates a circuit ...

Other materials:

Transmission Fluid Temperature Sensor "B" Circuit Short to Battery or Open (P274015)
DESCRIPTION The No. 2 ATF temperature sensor is installed in the transmission valve body assembly. If the ECM detects an abnormally high ATF temperature near this sensor, it illuminates the warning indicator. HINT: The temperature of ATF easily rises when towing, climbing hills, in traffic, ...

Tire Position Not Identified
DESCRIPTION The tire pressure warning ECU and receiver identifies the tire position for each tire pressure warning valve and transmitter according to the wheel speed signals from the skid control ECU and acceleration rate signal from each acceleration sensor built into each tire pressure warn ...

Precaution
PRECAUTION PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL NOTICE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected. Click here IGNITION SWITCH EXPRESSIONS (a) The type of ignition switch ...

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