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
HINT:
Remove the hydraulic brake booster before the inspection (See page
.gif)
).
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
hydraulic brake booster and brake booster pump (See page
).
Torque:
2.9 N·m {30 kgf·cm, 26 in·lbf}
| NG | .gif) |
RETIGHTEN SCREWS |
|
.gif)
|
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 |
|
|
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.
|
Result |
Proceed to |
|---|---|
|
DTC output |
A |
|
DTC not output |
B |
| A | |
REPLACE MASTER CYLINDER SOLENOID |
| B | |
END |
Open Circuit in IG1/IG2 Power Source Circuit (C1242)
DESCRIPTION
If there is a problem with the skid control ECU (master cylinder solenoid) power
supply circuit, the skid control ECU outputs the DTC and prohibits operation under
the fail safe funct ...
Brake Booster Pump Motor on Time Abnormally Long (C1252)
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).
...
Other materials:
Off-road precautions (4WD models and PreRunner)
This vehicle has higher ground clearance and narrower tread in relation to
the height of its center of gravity to make it capable of performing in a wide variety
of off-road applications.
Off-road vehicle feature
● Specific design characteristics give it a higher center of gravity than o ...
Driving the vehicle
The following procedures should be observed to ensure safe driving.
■ Starting the engine
■ Driving
Automatic transmission
With the brake pedal depressed,
shift the shift lever to D.
Release the parking brake.
Gradually release the brake pedal
and gently depress the acceler ...
Key Cannot be Registered
DESCRIPTION
A maximum of 5 master key ID codes can be registered.
WIRING DIAGRAM
Refer to "B2780" (See page )
CAUTION / NOTICE / HINT
NOTICE:
If the transponder key ECU assembly is replaced, refer to Registration (See page
).
PROCEDURE
1.
CHECK REGISTRATIO ...
