Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Engine / Cruise Control / Dynamic Radar Cruise Control System(for Gasoline Model) / Lost Communication with ECM / PCM "A" (U0100,U0125,U0126,U0129)

DESCRIPTION

The driving support ECU assembly communicates 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 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the ECM and driving support ECU assembly is detected for approximately 1 second or more.	CAN communication system ECM Driving support ECU assembly	Does not come on
U0125	Lost Communication with Yaw Rate Sensor Module	While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the yaw rate and acceleration sensor (airbag sensor assembly) and driving support ECU assembly is detected for approximately 1 second or more.	CAN communication system Yaw rate and acceleration sensor (Airbag sensor assembly) Driving support ECU assembly	Does not come on
U0126	Lost Communication with Steering Angle Sensor Module	While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the steering sensor and driving support ECU assembly is detected for approximately 1 second or more.	CAN communication system Steering sensor Driving support ECU assembly	Does not come on
U0129	Lost Communication with Brake System Control Module	While the vehicle speed is 5 km/h (3 mph) or more and the dynamic radar cruise control system is operating, a communication error between the skid control ECU (brake actuator assembly) and driving support ECU assembly is detected for approximately 2.5 seconds or more.	CAN communication system Skid control ECU (Brake actuator assembly) Driving support ECU assembly	Does not come on

PROCEDURE

1.	CHECK FOR DTCs

(a) Clear the DTCs.

Powertrain > Radar Cruise2 > 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.

Powertrain > Radar Cruise2 > Trouble Codes

Result	Proceed to
DTC U0100, U0125, U0126 and U0129 are not output	A
DTC U0100, U0125, U0126 or U0129 is output	B

USE SIMULATION METHOD TO CHECK

GO TO CAN COMMUNICATION SYSTEM

Terminals Of Ecu

Lost Communication with Cruise Control Front Distance Range Sensor (U0235)

See More:

Toyota Avalon (XX50) 2019-2022 Owners Manual > Using the driving support systems: Dynamic radar cruise controlwith full-speed range
Summary of functions In vehicle-to-vehicle distance control mode, the vehicle automatically accelerates, decelerates and stops to match the speed changes of the preceding vehicle even if the accelerator pedal is not depressed. In constant speed control mode, the vehicle runs at a fixed speed. Use th ...