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:
Fail-safe Chart
FAIL-SAFE CHART
HINT:
If any of the following auto cancel conditions are detected while the dynamic
radar cruise control system is controlling vehicle speed, the system clears the
stored vehicle speed and cancels control of vehicle speed by the dynamic radar cruise
control system.
Automatic ...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
HINT:
If a trouble code is displayed during the DTC check, inspect the trouble areas
listed for that code. For details of the code, refer to the "See page" below.
Seat Heater System
DTC Code
Detection Item
See page
...
Inspection
INSPECTION
PROCEDURE
1. INSPECT CHARCOAL CANISTER ASSEMBLY
(a) Visually check the charcoal canister assembly.
(1) Visually check the charcoal canister assembly for cracks or damage.
If cracks or damage are found, replace the charcoal canister assembly.
...
