TTGuideTacoma manuals & technical reference
Toyota Tacoma (2015-2018) Service Manual / Cruise Control / Dynamic Radar Cruise Control System(for 2gr-fks) / Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

Toyota Tacoma (2015-2018) Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

DESCRIPTION

The millimeter wave radar sensor assembly and ECM communicate with each sensor and ECU via CAN communication.

If any malfunction is detected in a CAN communication circuit, one or more CAN communication system DTCs are stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

U0100

Lost Communication with ECM / PCM "A"

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the ECM and the millimeter wave radar sensor assembly is detected for approximately 1 second or more.
  • CAN communication system
  • ECM
  • Millimeter wave radar sensor assembly

Does not come on

U0125

Lost Communication with Yaw Rate Sensor Module

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the yaw rate sensor and the millimeter wave radar sensor assembly is detected for approximately 1 second or more.
  • CAN communication system
  • Yaw rate sensor (airbag sensor assembly)
  • Millimeter wave radar sensor assembly

Does not come on

U0126

Lost Communication with Steering Angle Sensor Module

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the steering angle sensor and the millimeter wave radar sensor assembly is detected for approximately 1 second or more.
  • CAN communication system
  • Steering angle sensor
  • Millimeter wave radar sensor assembly

Does not come on

U0129

Lost Communication with Brake System Control Module

While the vehicle speed is 36 km/h (22 mph) or more and the dynamic radar cruise control system is operating, a communication error between the skid control ECU (master cylinder solenoid)*1 or skid control ECU (brake actuator assembly)*2 and the millimeter wave radar sensor assembly is detected for approximately 2.5 seconds or more.
  • CAN communication system
  • Skid control ECU (master cylinder solenoid)*1
  • Skid control ECU (brake actuator assembly)*2
  • Millimeter wave radar sensor assembly

Does not come on
  • *1: for Hydraulic Brake Booster
  • *2: for Vacuum Brake Booster

PROCEDURE

1.

CHECK FOR DTCs (RADAR CRUISE 1 AND RADAR CRUISE 2)

(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.

  1. Turn the ignition switch to ON.
  2. Turn the dynamic radar cruise control system on using the cruise control main switch (ON-OFF button).
  3. Drive the vehicle at 36 km/h (22 mph) or more for 5 seconds or more.

(c) Check for DTCs.

Click here

Result

Proceed to

DTC U0100, U0125, U0126 and U0129 are not output

A

DTC U0100, U0125, U0126 or U0129 is output

B
A

USE SIMULATION METHOD TO CHECK

B

GO TO CAN COMMUNICATION SYSTEM

    Related Tacoma materials

    LVDS Signal Malfunction (from Extension Module) (B1532)
    DESCRIPTION The stereo component tuner assembly and the radio and display receiver assembly are connected by an LVDS communication line. This DTC is stored when an LVDS communication error occurs between the stereo component tuner assembly and the radio and display receiver assembly. ...

    Vehicle Information Not Obtained (C1A02)
    DESCRIPTION When a new millimeter wave radar sensor assembly is installed, it receives vehicle specification information (destination, steering wheel position, 2WD or 4WD, etc.) from the main body ECU (multiplex network body ECU) and stores the information. DTC C1A02 is stored when the millime ...

    Turn Signal Lever Operation
    Operating instructions Move the turn signal lever to indicate a right turn with the Toyota Tacoma. For a lane change to the right, move the lever partway in the appropriate direction and then release it.The right turn signals will automatically flash 3 times to indicate the intended lane change ...