Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Open in Pump Motor Circuit (C1251)

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

C1251

Open in motor system circuit (motor input circuit)

Hydraulic brake booster pump motor circuit

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION / NOTICE / HINT

HINT:

Remove the hydraulic brake booster before the inspection (See page PROCEDURE ).

PROCEDURE

1.

CHECK BRAKE PUMP MOTOR WIRE HARNESS CONNECTION (MT+ / MT-)

(a) Using a screwdriver, remove the 2 plugs from the hydraulic brake booster (See page (b) Check the tightening torque of 2 screws which fasten the wire harness connecting ).

(b) Check the tightening torque of 2 screws which fasten the wire harness connecting hydraulic brake booster and brake booster pump (See page Torque: ).

Torque:

2.9 N·m {30 kgf·cm, 26 in·lbf}

NG

RETIGHTEN SCREWS

OK

2.

CHECK RESISTANCE OF PUMP MOTOR WIRE HARNESS (MT+/MT-)

(a) Using a screwdriver, remove the 2 screws and pull the wire harness from the hydraulic brake booster.

(b) Measure the resistance between the red wire (MT+) and black wire (MT-).

Resistance:

2 Ω

NG

REPLACE HYDRAULIC BRAKE BOOSTER

OK

3.

RECONFIRM DTC

(a) Reassemble the hydraulic brake booster, then reinstall the hydraulic brake booster.

(b) Clear the DTCs (See page ). (c) Check if the same DTCs are detected. ).

(c) Check if the same DTCs are detected.

Result

Proceed to

DTC output

A

DTC not output

B

A

REPLACE MASTER CYLINDER SOLENOID

B

END

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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). ...

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