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:
Steering Angle Sensor Initialization Incomplete (C1439,C1445)
DESCRIPTION
The skid control ECU (brake actuator assembly) acquires steering angle sensor
zero point every time the ignition switch is turned ON and the vehicle is driven
at 35 km/h (22 mph) or more for approximately 5 seconds. The ECU also stores the
previous zero point.
The steering angle ...
Disassembly
DISASSEMBLY
CAUTION / NOTICE / HINT
NOTICE:
Do not try to remove the black nylon tube as it is welded to the fuel suction
tube assembly (See page
).
PROCEDURE
1. REMOVE FUEL SENDER GAUGE ASSEMBLY
2. REMOVE NO. 1 FUEL SUB-TANK
(a) Disconnect the 2 fuel pump connectors.
...
Registration
REGISTRATION
PROCEDURE
1. BEFORE REGISTRATION
NOTICE:
The transmitter ID is written on the tire pressure warning valve and transmitter.
It is not possible to read the transmitter ID after installing the tire onto the
wheel. Therefore, make a note of the transmitter ID before installing the t ...
