Toyota Tacoma (2015-2018) Service Manual: Pressure Sensor or Switch (C1254)
DESCRIPTION
The accumulator pressure sensor is connected to the skid control ECU in the master cylinder solenoid.
|
DTC No. |
DTC Detecting Condition |
Trouble Areas |
|---|---|---|
|
C1254 |
Accumulator pressure sensor fault (Fluid pressure does not change when it should e.g. pump operates, brake pedal depressed/released). |
|
PROCEDURE
|
1. |
READ VALUE USING DATA LIST (ACCUMULATOR SENSOR) |
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Select the Data List mode on the Techstream.
ABS/VSC/TRAC|
Tester Display |
Measurement Item / Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Accumulator Sensor |
Accumulator pressure sensor reading / min.: 0 V, max.: 5 V |
3.58 to 5 V |
- |
(f) Confirm whether the accumulator output voltage is normal.
|
Result |
Proceed to |
|---|---|
|
Output value normal |
A |
|
Output value not normal |
B |
| B | .gif) |
REPLACE MASTER CYLINDER SOLENOID |
|
.gif)
|
2. |
READ VALUE USING DATA LIST (MASTER CYLINDER PRESSURE SENSOR) |
(a) Turn the ignition switch to OFF.
(b) Depress the brake pedal more than 20 times.
(c) Install a brake pedal effort gauge (SST), and bleed air.
(d) Connect Techstream to the DLC3.
(e) Turn the ignition switch to the ON position.
(f) Select the Data List mode on the Techstream.
ABS/VSC/TRAC|
Tester Display |
Measurement Item / Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
Master Cylinder Sensor |
Master cylinder pressure sensor reading / min.: 0 V, max.: 5 V |
0.3 to 1.9 V With pedal pressure of 49 N (5 kgf, 11 lbf) |
Front brake pressure: 770 to 1280 kPa (7.9 to 13.1 kgf/cm2, 112 to 186 psi) |
(g) Check that the master cylinder output value is in the Normal Condition range.
OK:
Master cylinder pressure sensor value is in the Normal Condition.
| NG | |
REPLACE MASTER CYLINDER SOLENOID |
|
|
3. |
RECONFIRM DTC |
(a) Clear the DTCs (See page .gif)
).
(b) Turn the ignition switch to OFF.
(c) Depress the brake pedal more than 20 times.
(d) Turn the ignition switch to the ON position.
(e) Wait until the pump motor stops.
(f) Depress the brake pedal and release it.
(g) Wait for 25 minutes.
(h) Check if the same DTCs are recorded.
|
Result |
Proceed to |
|---|---|
|
DTC output |
A |
|
DTC not output |
B |
| A | |
REPLACE MASTER CYLINDER SOLENOID |
| B | |
END |
Pump Motor Relay (C1253)
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).
...
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
...
Other materials:
System Diagram
SYSTEM DIAGRAM
Transmitting ECU (Transmitter)
Receiving ECU
Signal
Communication Method
4 wheel drive control ECU
Skid control ECU (Brake actuator assembly)
High-Low actuator fail
4WD status ...
Vehicle Speed Sensor "A" No Signal (P050031)
DESCRIPTION
Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle
speed using the skid control ECU (brake actuator assembly) and speed sensors. Each
speed sensor monitors the wheel rotation speed and sends a signal to the skid control
ECU. The skid control ECU con ...
Reassembly
REASSEMBLY
PROCEDURE
1. INSTALL REAR AXLE HUB BOLT
(a) Install a new deflector gasket and deflector onto the rear axle shaft.
HINT:
Align the 2 notches.
(b) Install the 6 bolts through the axle hub.
...
