Toyota CH-R Service Manual: Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129,U023A)

Toyota CH-R Service Manual / Pre-collision / Pre-collision System / Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129,U023A)

DESCRIPTION

These DTCs are stored when a communication malfunction occurs between ECUs that perform pre-collision control.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

U0100

Lost Communication with ECM / PCM "A"

When driving the vehicle at a speed of 5 km/h (4 mph) or more, a communication error between the ECM and the millimeter wave radar sensor assembly is detected for approximately 5 seconds.
  • CAN communication system
  • ECM
  • Millimeter wave radar sensor assembly
  • Wire harness or connector

U0125

Lost Communication with Yaw Rate Sensor Module

When driving the vehicle at a speed of 5 km/h (4 mph) or more, a communication error between the yaw rate and acceleration sensor (airbag sensor assembly) and the millimeter wave radar sensor assembly is detected for approximately 1 second.
  • CAN communication system
  • Yaw rate and acceleration sensor (Airbag sensor assembly)
  • Millimeter wave radar sensor assembly
  • Wire harness or connector

U0126

Lost Communication with Steering Angle Sensor Module

When the ignition switch is ON, a communication error between the steering angle sensor (spiral cable with sensor sub-assembly) and the millimeter wave radar sensor assembly is detected for approximately 4 seconds.
  • CAN communication system
  • Steering angle sensor (Spiral cable with sensor sub-assembly)
  • Millimeter wave radar sensor assembly
  • Wire harness or connector

U0129

Lost Communication with Brake System Control Module

When the ignition switch is ON, a communication error between the skid control ECU (brake actuator assembly) and the millimeter wave radar sensor assembly is detected for approximately 3 seconds.
  • CAN communication system
  • Skid control ECU (Brake actuator assembly)
  • Millimeter wave radar sensor assembly
  • Wire harness or connector

U023A

Lost Communication with Front Camera Module

After the ignition switch is turned ON, a communication malfunction occurs between the millimeter wave radar sensor assembly and forward recognition camera.
  • CAN communication system
  • Forward recognition camera
  • Millimeter wave radar sensor assembly
  • Wire harness or connector

PROCEDURE

1.

CHECK FOR DTCs (PRE-COLLISION SYSTEM)

(a) Clear the DTCs.

Click here

Body Electrical > Pre-Collision 2 > Clear DTCs

(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

Body Electrical > Pre-Collision 2 > Trouble Codes

Result

Proceed to

DTC U0100, U0125, U126 and U0129 are not output

A

DTC U0100, U0125, U126 or U0129 is output

B
A

USE SIMULATION METHOD TO CHECK

B

GO TO CAN COMMUNICATION SYSTEM

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