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.
Click here
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 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

Front Camera Module Beam Axis Not Adjusted (C1AA9)

DESCRIPTION If forward recognition camera adjustment has not been performed or did not complete normally after the forward recognition camera was replaced with a new one, DTC C1AA9 will be stored ...

Other System Malfunction (C1A63)

DESCRIPTION The millimeter wave radar sensor assembly receives accelerator pedal position sensor signals from the ECM to determine if the accelerator pedal is being depressed. If the ECM detects ...

Other materials:

Main Switch Illumination Circuit
DESCRIPTION When the light control switch is turned to the tail or head position, this circuit sends an illumination signal to the wireless charger main switch (mobile wireless charger switch). Based on this signal, the wireless charger main switch (mobile wireless charger switch) is illumina ...

Steering Pad Switch Circuit
DESCRIPTION The forward recognition camera receives a lane departure alert switch signal from the steering pad switch assembly. WIRING DIAGRAM for 2TR-FE for 2GR-FKS CAUTION / NOTICE / HINT NOTICE: The vehicle is equipped with a Supplemental Restraint System (SRS) which includes compo ...

Lost Communication with Cruise Control Front Distance Range Sensor (U0235)
DESCRIPTION The millimeter wave radar sensor assembly is connected to the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 via CAN communication. If communication with the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake act ...