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:
Invalid Data Received From Vehicle Dynamics Control Module (U0416)
DESCRIPTION
This DTC is detected if a wheel speed malfunction signal is sent from the skid
control ECU (brake actuator assembly).
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
U0416
Invalid Data Received From V ...
CD Sound Skips
PROCEDURE
1.
CHECK CD
(a) Check that the CD is not deformed or cracked.
OK:
No deformation or cracks on the CD
NG
CD IS FAULTY
OK
...
Replacement
REPLACEMENT
PROCEDURE
1. REPLACE INTAKE VALVE GUIDE BUSH
(a) Heat the cylinder head to 80 to 100°C (176 to 212°F).
(b) Place the cylinder head on wooden blocks.
(c) Using SST and a hammer, tap out the intake valve guide bushes.
SST: 09201-10000
09201-01050
SST: 09950-70010 ...