Toyota Tacoma 2015-2018 Service Manual: Power Supply Drive Circuit (C1257)
DESCRIPTION
The motor relay (semiconductor relay) is built into the hydraulic brake booster and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).
|
DTC No. |
DTC Detecting Condition |
Trouble Areas |
|---|---|---|
|
C1257 |
Open in pump motor input circuit |
Hydraulic brake booster pump motor circuit |
PROCEDURE
|
1. |
CHECK HYDRAULIC BRAKE BOOSTER PUMP MOTOR OPERATION |
(a) Turn the ignition switch to OFF.
(b) Disconnect the actuator connector (S1).
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Check the hydraulic brake booster pump motor operation.
OK:
Hydraulic brake booster pump operates.
| NG | .gif) |
REPLACE MASTER CYLINDER SOLENOID |
|
.gif)
|
2. |
RECONFIRM DTC |
(a) Turn the ignition switch to OFF.
(b) Reconnect the actuator connector (S1).
(c) Turn the ignition switch to the ON position.
(d) Clear the DTCs (See page .gif)
).
(e) Check if the same DTCs are recorded.
|
Result |
Proceed to |
|---|---|
|
DTC output |
A |
|
DTC not output |
B |
| A | |
REPLACE MASTER CYLINDER SOLENOID |
| B | |
END |
Accumulator Low Pressure (C1256)
DESCRIPTION
The accumulator pressure sensor is connected to the skid control ECU in the master
cylinder solenoid.
DTC No.
DTC Detecting Condition
Trouble Areas
...
Transfer L4 Position Switch Circuit (C1268)
DESCRIPTION
A-TRAC is activated if wheel skid is detected while the transfer is in the L4
position.
DTC Code
DTC Detecting Condition
Trouble Areas
...
Other materials:
Removal
REMOVAL
PROCEDURE
1. REMOVE CLUTCH MASTER CYLINDER ASSEMBLY
(See page )
2. REMOVE TURN OVER SPRING SEAT COMPRESSION SPRING
(a) Remove the compression spring.
3. REMOVE CLUTCH PEDAL SUB-ASSEMBLY
(a) Remove the bolt and nut.
...
Wireless remote control battery
Replace the battery with a new one if it is discharged.
■ You will need the following items:
Lithium battery CR2032
■ Replacing the battery
Remove the cover using a coin protected with tape etc.
Remove the discharged transmitter battery.
Insert a new battery with the “+” te ...
Master Cylinder Pressure Sensor Zero Point High Malfunction (C1422,C1456)
DESCRIPTION
Refer to DTCs C1421, C1423, C1424, C1455, C1457 and C1458 (See page
).
DTC Code
DTC Detection Condition
Trouble Area
C1422
When the stop light switch is off, the PM/C1 terminal voltage is 0.86
V or higher for 5 seconds ...
