Toyota Tacoma manuals

Toyota Tacoma 2015-2018 Service Manual: Brake Control Signal Mismatch (C1A69)

DESCRIPTION

The skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 sends signals to the millimeter wave radar sensor assembly according to the brake control status. 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, it will store DTC C1A64.

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C1A69

Brake Control Signal Mismatch

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 C1A69 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

GO TO VEHICLE STABILITY CONTROL SYSTEM

A

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.

(c) Check for DTCs.

Click here

Result

Proceed to

DTC C1A69 is not output

A

DTC C1A69 is output

B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY

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 ...

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 ...

Other materials:

Disassembly
DISASSEMBLY PROCEDURE 1. REMOVE STEERING GEAR OUTLET RETURN TUBE (a) Using a union nut wrench, remove the steering gear outlet return tube. 2. REMOVE STEERING TURN PRESSURE TUBE (a) Using a union nut wrench, remove the 2 pressure tubes. (b) Remove the 4 O-rings from the pressure tubes. 3. ...

Data List / Active Test
DATA LIST / ACTIVE TEST 1. DATA LIST Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be ...

Test Mode Procedure
TEST MODE PROCEDURE 1. TEST MODE PROCEDURE (for Using Techstream) HINT: If the ignition switch is turned from the ON to the ACC or LOCK position during test mode, DTCs related to the signal check function will be cleared. During test mode, the skid control ECU (master cylinder ...

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