Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Pressure Sensor or Switch (C1254)

DESCRIPTION

The accumulator pressure sensor is connected to the skid control ECU in the master cylinder solenoid.

DTC No.

DTC Detecting Condition

Trouble Areas

C1254

Accumulator pressure sensor fault

(Fluid pressure does not change when it should e.g. pump operates, brake pedal depressed/released).

  • Hydraulic brake booster
  • Accumulator pressure sensor
  • Master cylinder pressure sensor

PROCEDURE

1.

READ VALUE USING DATA LIST (ACCUMULATOR SENSOR)

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to OFF.

(c) Depress the brake pedal more than 20 times.

(d) Turn the ignition switch to the ON position.

(e) Select the Data List mode on the Techstream.

ABS/VSC/TRAC

Tester Display

Measurement Item / Range

Normal Condition

Diagnostic Note

Accumulator Sensor

Accumulator pressure sensor reading / min.: 0 V, max.: 5 V

3.58 to 5 V

-

(f) Confirm whether the accumulator output voltage is normal.

Result

Proceed to

Output value normal

A

Output value not normal

B

B

REPLACE MASTER CYLINDER SOLENOID

A

2.

READ VALUE USING DATA LIST (MASTER CYLINDER PRESSURE SENSOR)

(a) Turn the ignition switch to OFF.

(b) Depress the brake pedal more than 20 times.

(c) Install a brake pedal effort gauge (SST), and bleed air.

(d) Connect Techstream to the DLC3.

(e) Turn the ignition switch to the ON position.

(f) Select the Data List mode on the Techstream.

ABS/VSC/TRAC

Tester Display

Measurement Item / Range

Normal Condition

Diagnostic Note

Master Cylinder Sensor

Master cylinder pressure sensor reading / min.: 0 V, max.: 5 V

0.3 to 1.9 V

With pedal pressure of 49 N (5 kgf, 11 lbf)

Front brake pressure: 770 to 1280 kPa (7.9 to 13.1 kgf/cm2, 112 to 186 psi)

(g) Check that the master cylinder output value is in the Normal Condition range.

OK:

Master cylinder pressure sensor value is in the Normal Condition.

NG

REPLACE MASTER CYLINDER SOLENOID

OK

3.

RECONFIRM DTC

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

(b) Turn the ignition switch to OFF.

(c) Depress the brake pedal more than 20 times.

(d) Turn the ignition switch to the ON position.

(e) Wait until the pump motor stops.

(f) Depress the brake pedal and release it.

(g) Wait for 25 minutes.

(h) Check if the same DTCs are recorded.

Result

Proceed to

DTC output

A

DTC not output

B

A

REPLACE MASTER CYLINDER SOLENOID

B

END

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