Toyota Tacoma (2015-2018) Service Manual: Open in Stop Light Switch Circuit (C1425)
DESCRIPTION
The skid control ECU (brake actuator assembly) detects the brake operating conditions through a signal transmitted by the stop light switch.
The skid control ECU incorporates a circuit to detect an open circuit. This DTC is output when an open circuit is detected in the stop light signal input line.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1425 |
Open in Stop Light Switch Circuit |
When voltage at terminal +BS is 9.5 to 17.4 V, open circuit occurs between STP terminal circuits A and B for 0.3 seconds or more. |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
When replacing the skid control ECU (brake actuator assembly), perform zero point
calibration and store system information (See page
.gif)
).
PROCEDURE
|
1. |
CHECK STOP LIGHT OPERATION |
(a) Check that all stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.
OK:
|
Condition |
Illumination Condition |
|---|---|
|
Brake pedal depressed |
ON |
|
Brake pedal released |
OFF |
| NG | .gif) |
CHECK STOP LIGHT CIRCUIT |
|
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|
2. |
CHECK HARNESS AND CONNECTOR (STP TERMINAL) |
|
(a) Turn the ignition switch off. |
|
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(b) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(c) Disconnect the S1 skid control ECU (brake actuator assembly) connector.
(d) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
S1-35 (STP) - Body ground |
Stop light switch assembly on (Brake pedal depressed) |
8 to 14 V |
|
Stop light switch assembly off (Brake pedal released) |
Below 1.5 V |
|
*a |
Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly]) |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - STOP LIGHT CIRCUIT) |
|
|
3. |
RECONFIRM DTC |
(a) Reconnect the S1 skid control ECU (brake actuator assembly) connector.
(b) Clear the DTCs (See page
).
(c) Turn the ignition switch off.
(d) Start the engine.
(e) Depress the brake pedal several times to test the stop light circuit.
(f) Check if the same DTC is recorded (See page
).
HINT:
If troubleshooting has been carried out according to the Problem Symptoms Table,
refer back to the table and proceed to the next step (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1425 is not output |
A |
|
DTC C1425 is output |
B |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
Master Cylinder Pressure Sensor Zero Point High Malfunction (C1422)
DESCRIPTION
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
C1422
Master Cylinder Pressure Sensor Zero Point High M ...
Stop Light Switch OFF Stuck Malfunction (C1426)
DESCRIPTION
The skid control ECU (brake actuator assembly) inputs the stop light signal and
brake operation condition. When the brake pedal is depressed and the stop light
switch signal is not in ...
Other materials:
Engine Switch
Components
COMPONENTS
ILLUSTRATION
Inspection
INSPECTION
PROCEDURE
1. INSPECT ENGINE SWITCH
(a) Measure the resistance according to the value(s) in the table below.
Text in Illustration
*a
Component without harness connected
(Engine Switch)
-
...
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
C1268
L4 detection switch signal input to skid control ECU (master cylinder
solenoid ...
Reassembly
REASSEMBLY
PROCEDURE
1. TEMPORARILY TIGHTEN FRONT DISC BRAKE BLEEDER PLUG
(a) Provisionally tighten the bleeder plug to the disc brake cylinder.
(b) Install the bleeder plug cap onto the bleeder plug.
2. INSTALL PISTON SEAL
(a) Apply lithium soap base glycol grease to 4 new piston s ...
