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:
Removal
REMOVAL
PROCEDURE
1. REMOVE STEERING PAD
(See page
)
2. REMOVE STEERING WHEEL ASSEMBLY
3. REMOVE LOWER STEERING COLUMN COVER
4. REMOVE UPPER STEERING COLUMN COVER
5. REMOVE SPIRAL CABLE SUB-ASSEMBLY WITH SENSOR
(a) Slide the slider and disconnect the airbag connect ...
Registration
REGISTRATION
PROCEDURE
1. DESCRIPTION OF CODE REGISTRATION
HINT:
Registering an ID code enables the entry and start function, wireless
door lock control function and engine immobiliser function to be operated.
Code registration is needed when the certification ECU (smart key E ...
Engine Immobiliser System Malfunction (B2799,B279986)
DESCRIPTION
This DTC is stored when one of the following occurs: 1) the ECM detects errors
in its own communication with the transponder key ECU assembly; 2) the ECM detects
errors in the communication lines; or 3) the ECU communication ID between the transponder
key ECU assembly and ECM is d ...
