Toyota Tacoma 2015-2018 Service Manual: Brake System Malfunction (C1A50)

Toyota Tacoma 2015-2018 Service Manual / Pre-collision / Pre-collision System / Brake System Malfunction (C1A50)

DESCRIPTION

When the pre-collision system is operating, the millimeter wave radar sensor assembly sends brake control signals to the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2.

If the millimeter wave radar sensor assembly receives a vehicle stability control system malfunction signal from the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 via CAN communication, DTC C1A50 will be stored.

*1: for Hydraulic Brake Booster
*2: for Vacuum Brake Booster

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1A50	Brake System Malfunction	While the ignition switch is ON, the millimeter wave radar sensor assembly receives a vehicle stability control system malfunction signal from the skid control ECU (master cylinder solenoid)1 or skid control ECU (brake actuator assembly)2 for 1 second or more.	Vehicle stability control system Millimeter wave radar sensor assembly

*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.
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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.
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PROCEDURE

1.	CHECK FOR DTCs (VEHICLE STABILITY CONTROL SYSTEM)

HINT:

Pre-collision system DTC C1A50 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

GO TO VEHICLE STABILITY CONTROL SYSTEM

2.	CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here (b) Make sure that the DTC detection conditions are met.

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

Click here

Result	Proceed to
DTC C1A50 is not output	A
DTC C1A50 is output	B

USE SIMULATION METHOD TO CHECK

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

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