Toyota Tacoma (2015-2018) Service Manual: 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 input, C1426 is output.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1426 |
Stop Light Switch OFF Stuck Malfunction |
When voltage at terminal +BS is 9.5 V or higher, vehicle is driven and brake pedal is operated, stop light switch signal is not input. |
|
WIRING DIAGRAM
Refer to DTC C1380 (See page .gif)
).
CAUTION / NOTICE / HINT
NOTICE:
- When replacing the skid control ECU (brake actuator assembly), perform
zero point calibration and store system information (See page
).
- Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
|
1. |
CHECK BRAKE PEDAL AND STOP LIGHT SWITCH INSTALLATION |
(a) Check the brake pedal height installation (See page
).
(b) Check the stop light switch assembly installation (See page
).
OK:
The brake pedal height and stop light switch assembly installation are normal.
HINT:
If the on/off status of the stop light switch assembly and pressure increase information from the master cylinder pressure sensor do not match due to an improperly installed brake pedal or stop light switch assembly, this DTC may be stored. Therefore, be sure to check the installation condition of the pedal and switch before inspecting the input signals and other related parts.
| NG | .gif) |
ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY |
|
.gif)
|
2. |
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 | |
GO TO STEP 5 |
|
|
3. |
READ VALUE USING TECHSTREAM (STOP LIGHT SWITCH ASSEMBLY) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Select the Data List using the Techstream (See page
).
|
Tester Display |
Measurement Item |
Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|---|
|
Stop Light SW |
Stop light switch |
ON or OFF |
ON: Brake pedal depressed OFF: Brake pedal released |
- |
(d) Check that the stop light switch display observed on the Techstream changes according to brake pedal operation.
OK:
The Techstream displays ON or OFF according to brake pedal operation.
| NG | |
GO TO STEP 8 |
|
|
4. |
RECONFIRM DTC |
(a) Turn the ignition switch off.
(b) Clear the DTCs (See page
).
(c) Start the engine.
(d) Depress the brake pedal several times to test the stop light circuit.
(e) Check if the same DTC is recorded (See page
).
|
Result |
Proceed to |
|---|---|
|
DTC C1426 is not output. |
A |
|
DTC C1426 is output. |
B |
HINT:
If troubleshooting has been carried out according to Problem Symptoms Table,
refer back to the table and proceed to the next step (See page
).
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
|
5. |
INSPECT STOP LIGHT SWITCH ASSEMBLY |
(a) Check the stop light switch assembly (See page
).
OK:
The stop light switch assembly is normal.
| NG | |
REPLACE STOP LIGHT SWITCH ASSEMBLY |
|
|
6. |
CHECK HARNESS AND CONNECTOR (STP TERMINAL) |
(a) Turn the ignition switch off.
|
(b) Make sure that there is no looseness at the locking part and the connecting part of the connector. |
|
.png)
(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 (STP CIRCUIT) |
|
|
7. |
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
).
|
Result |
Proceed to |
|---|---|
|
DTC C1426 is not output. |
A |
|
DTC C1426 is output. |
B |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT) |
|
8. |
CHECK HARNESS AND CONNECTOR (STP TERMINAL) |
(a) Turn the ignition switch off.
|
(b) Make sure that there is no looseness at the locking part and the connecting part of the connector. |
|
(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)) |
| OK | |
REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) |
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 ...
Motor Malfunction (C1427)
DESCRIPTION
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
C1427
Motor Malfunction
Actuator pump motor ...
Other materials:
Removal
REMOVAL
PROCEDURE
1. REMOVE REAR WHEEL
2. DRAIN BRAKE FLUID
HINT:
Immediately wash off any brake fluid that comes into contact with any painted
surfaces.
3. REMOVE REAR BRAKE DRUM SUB-ASSEMBLY
(a) Release the parking brake, and remove the rear brake drum.
If the rear brake drum cannot be ...
Reverse Signal Circuit
DESCRIPTION
The radio and display receiver assembly*1 or navigation receiver assembly*2 receives
a reverse signal from the park/neutral position switch*3 or the back-up light switch
assembly*4.
*1: w/o Navigation System
*2: w/ Navigation System
*3: for Automatic Transmission
...
Crankshaft Position Sensor "A" Signal Stuck in Range (P03352A,P033531)
DESCRIPTION
The crankshaft position sensor system consists of a crankshaft position sensor
plate and a pickup coil. The crankshaft position sensor plate has 34 teeth and is
installed to the crankshaft. The pickup coil is made of wound copper wire, an iron
core and a magnet. The crankshaft pos ...
