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:
On-vehicle Inspection
ON-VEHICLE INSPECTION
PROCEDURE
1. CHECK FUEL PUMP OPERATION AND INSPECT FOR FUEL LEAK
(a) Connect the Techstream to the DLC3.
(1) Turn the ignition switch to ON.
NOTICE:
Do not start the engine.
(2) Turn the Techstream on.
(3) Enter the following menus: Powertrain / Engine / Active Test / C ...
System Description
SYSTEM DESCRIPTION
1. TOUCH SWITCH OUTLINE
Touch switches are touch-sensitive (interactive) switches operated by touching
the screen. When a switch is pressed, the outer film bends in to contact the inner
glass at the pressed position. By doing this, the voltage ratio is measured and
the pre ...
Transmitter Battery(w/ Smart Key System)
Replacement
REPLACEMENT
CAUTION / NOTICE / HINT
NOTICE:
Take extra care when handling these precision electronic components.
PROCEDURE
1. REMOVE TRANSMITTER BATTERY
(a) Push the release hook knob and extract the mechanical key as shown
in the illustration.
Text in Illustra ...
