Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Pump Motor Relay (C1253)

DESCRIPTION

The motor relay (semiconductor relay) is built into the master cylinder solenoid and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

DTC No.

DTC Detecting Condition

Trouble Areas

C1253

Open in motor system circuit (motor input circuit)

  • Hydraulic brake booster pump motor
  • Hydraulic brake booster pump motor circuit

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the skid control ECU (master cylinder solenoid), perform zero point calibration (See page ). Inspect the fuses for circuits related to this system before performing ).
  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

Start the inspection from step 1 when using Techstream and start from step 3 when not using Techstream.

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (MOTOR RELAY)

(a) Connect Techstream to the DLC3.

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

(c) Turn Techstream ON.

(d) Select the Active Test mode on the Techstream.

ABS/VSC/TRAC

Tester Display

Test Part

Control Range

Diagnostic Note

Motor Relay

Turns motor relay

ON / OFF

Operation of motor can be heard

(e) Check for operation sound of the motor when it is operated with Techstream.

OK:

The operation sound of the motor can be heard.

NG

GO TO STEP 3

OK

2.

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 several times until the pump motor is turned on.

(g) Wait until the pump stops.

(h) Repeat (f) and (g) three times.

(i) Check if the same DTCs are recorded.

Result

Proceed to

DTC output

A

DTC not output

B

A

REPLACE HYDRAULIC BRAKE BOOSTER

B

END

3.

CHECK HARNESS AND CONNECTOR (+BM, +BM2 TERMINAL)

(a) Disconnect the skid control ECU (master cylinder solenoid) connectors.

(b) Measure the voltage.

Standard Voltage:

Tester Connection

Specified Condition

S1-2 (+BM1) - Body ground

10 to 14 V

S2-2 (+BM2) - Body ground

10 to 14 V

(c) Reconnect the skid control ECU (master cylinder solenoid) connectors.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM1 AND +BM2 CIRCUIT)

OK

4.

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BODY GROUND)

(a) Disconnect the skid control ECU (master cylinder solenoid) connectors.

(b) Measure the resistance.

Standard Resistance:

Tester Connection

Specified Condition

S1-1 (GND1) - Body ground

Below 1 Ω

S1-32 (GND2) - Body ground

Below 1 Ω

S2-4 (GND3) - Body ground

Below 1 Ω

(c) Reconnect the skid control ECU (master cylinder solenoid) connectors.

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

OK

5.

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 several times until the pump motor is turned on.

(g) Wait until the pump stops.

(h) Repeat (f) and (g) three times.

(i) Check if the same DTCs are recorded.

Result

Proceed to

DTC output

A

DTC not output

B

A

REPLACE HYDRAULIC BRAKE BOOSTER

B

END

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