Toyota Tacoma (2015-2018) Service Manual: Stop Light Relay Circuit (C1A4B)
DESCRIPTION
The skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 sends a stop light operation request signal to the stop light relay (stop light switch assembly). If the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 detects a malfunction in the stop light relay circuit, the millimeter wave radar sensor assembly stores DTC C1A4B.
- *1: for Hydraulic Brake Booster
- *2: for Vacuum Brake Booster
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
|---|---|---|---|
|
C1A4B |
Stop Light Relay Circuit |
While the ignition switch is ON, the millimeter wave radar sensor assembly receives a stop light relay circuit malfunction signal from the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 for 1 second or more. |
|
- *1: for Hydraulic Brake Booster
- *2: for Vacuum Brake Booster
CAUTION / NOTICE / HINT
NOTICE:
- When replacing the millimeter wave radar sensor assembly, always replace it with a new one. If a millimeter wave radar sensor assembly which was installed to another vehicle is used, the information stored in the millimeter wave radar sensor assembly will not match the information from the vehicle. As a result, a DTC may be stored.
- If the millimeter wave radar sensor assembly has been replaced, be sure
to perform millimeter wave radar sensor assembly adjustment.
Click here
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- The pre-collision system uses the CAN communication system. First, confirm
that there are no malfunctions in the CAN communication system. Refer to
How to Proceed with Troubleshooting.
Click here
PROCEDURE
|
1. |
CHECK FOR DTCs (VEHICLE STABILITY CONTROL SYSTEM) |
HINT:
Pre-collision system DTC C1A4B may be stored due to a malfunction in the vehicle stability control system. Therefore, it is necessary to check for and troubleshoot vehicle stability control system DTCs first.
(a) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
Vehicle stability control system DTCs are not output |
A |
|
Vehicle stability control system DTCs are output |
B |
| B | .gif) |
GO TO VEHICLE STABILITY CONTROL SYSTEM |
|
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|
2. |
CHECK FOR DTCs (PRE-COLLISION SYSTEM) |
(a) Clear the DTCs.
Click here
(b) Make sure that the DTC detection conditions are met.
HINT:
If the detection conditions are not met, the system cannot detect the malfunction.
(c) Check for DTCs.
Click here
|
Result |
Proceed to |
|---|---|
|
DTC C1A4B is not output |
A |
|
DTC C1A4B is output |
B |
| A | |
USE SIMULATION METHOD TO CHECK |
| B | |
REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY |
Skid Control Buzzer Circuit (C1A4A)
DESCRIPTION
The millimeter wave radar sensor assembly is connected to the forward recognition
camera via CAN communication.
The millimeter wave radar sensor assembly operates the pre-collision ala ...
Steering Angle Sensor (C1A47)
DESCRIPTION
The millimeter wave radar sensor assembly receives steering angle information
from the steering angle sensor (spiral cable with sensor sub-assembly). If the millimeter
wave radar sens ...
Other materials:
4WD Control Switch Circuit
WIRING DIAGRAM
PROCEDURE
1.
CONFIRM PROBLEM SYMPTOM
(a) Confirm the problem symptoms.
Result
Result
Proceed to
The 4WD indicator light (green) and 4LO indicator light remain off
A
The 4WD indica ...
Precaution
PRECAUTION
1. IGNITION SWITCH EXPRESSIONS
(a) The type of ignition switch used on this model differs according to the specifications
of the vehicle. The expressions listed in the table below are used in this section.
Expression
Ignition Switch (Position)
Engine ...
Installation
INSTALLATION
PROCEDURE
1. INSTALL STEERING PAD
(a) Check that the ignition switch is off.
(b) Check that the cable is disconnected from the negative (-) battery terminal.
CAUTION:
Wait at least 90 seconds after disconnecting the cable from the negative (-)
battery terminal to disable the SRS ...
