Toyota Yaris: Stop And Start System / Lost Communication with ECM/PCM "A" Missing Message (U010087,U012687,U012987,U013187,U014087,U015187,U015587,U016487,U117087)

Toyota Yaris XP210 (2020-2024) Reapir and Service Manual / Engine & Hybrid System / Stop And Start / Stop And Start System / Lost Communication with ECM/PCM "A" Missing Message (U010087,U012687,U012987,U013187,U014087,U015187,U015587,U016487,U117087)

DESCRIPTION

The engine stop and start ECU communicates with the SFI system, electronically controlled brake system, power steering system, air conditioning system, airbag system and main body ECU (multiplex network body ECU) via CAN communication.

If there is a communication error between the engine stop and start ECU and any of the systems, the engine stop and start ECU stores DTCs and illuminates the stop and start cancel indicator except when there is a communication error with the meter / gauge system.

HINT:

When there is an open in the output side of the backup boost converter (built into the engine stop and start ECU), power to the system with the open is cut off. The engine stop and start ECU stores CAN communication DTCs for the system with the open and stop and start system DTC P323A16.
When the backup boost converter (built into the engine stop and start ECU) detects overcurrent in any of the circuits it supplies power to, it shuts off the circuit. The engine stop and start ECU stores CAN communication DTCs for the system which circuit was shut off and stores stop and start system DTC P323A19.
e.g.: When the backup boost converter (built into the engine stop and start ECU) detects overcurrent in the power source circuit of the power steering system and cuts off power supply, the engine stop and start ECU stores DTCs U013187 and P323A19.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory	Note
U010087	Lost Communication with ECM/PCM "A" Missing Message	No communication between the engine stop and start ECU and ECM for 1 second.	Wire harness or connector Engine stop and start ECU ECM	Blinks	DTC stored	SAE Code: U0100
U012687	Lost Communication with Steering Angle Sensor Module Missing Message	No communication between the engine stop and start ECU and steering sensor for 1 second.	Wire harness or connector Engine stop and start ECU Steering sensor	Blinks	DTC stored	SAE Code: U0126
U012987	Lost Communication with Brake System Control Module Missing Message	No communication between the engine stop and start ECU and skid control ECU (brake actuator assembly) for 2.22 seconds.	Wire harness or connector Engine stop and start ECU Skid control ECU (Brake actuator assembly)	Blinks	DTC stored	SAE Code: U0129
U013187	Lost Communication with Power Steering Control Module Missing Message	No communication between the engine stop and start ECU and the power steering ECU (rack and pinion power steering gear assembly) for 1 second.	Wire harness or connector Engine stop and start ECU Power steering ECU (Rack and pinion power steering gear assembly)	Blinks	DTC stored	SAE Code: U0131
U014087	Lost Communication with Body Control Module Missing Message	No communication between the engine stop and start ECU and the main body ECU (multiplex network body ECU) for 3.6 seconds.	Wire harness or connector Engine stop and start ECU Main body ECU (multiplex network body ECU)	Blinks	DTC stored	SAE Code: U0140
U015187	Lost Communication with Restraints Control Module Missing Message	No communication between the engine stop and start ECU and airbag sensor assembly for 10.6 seconds.	Wire harness or connector Engine stop and start ECU Airbag sensor assembly	Blinks	DTC stored	SAE Code: U0151
U015587	Lost Communication with Instrument Panel Cluster (IPC) Control Module Missing Message	No communication between the engine stop and start ECU and the combination meter assembly for 4 second	Wire harness or connector Engine stop and start ECU Combination meter assembly	Blinks	DTC stored	SAE Code: U0155
U016487	Lost Communication with HVAC Control Module Missing Message	No communication between the engine stop and start ECU and air conditioning amplifier assembly for 10.6 seconds.	Wire harness or connector Engine stop and start ECU Air conditioning amplifier assembly	Blinks	DTC stored	SAE Code: U0164
U117087	Lost Communication With Brake System Control Module(ch2) Missing Message	No communication between the engine stop and start ECU and the skid control ECU (brake actuator assembly) for 3 second	Wire harness or connector Engine stop and start ECU Skid control ECU (brake actuator assembly)	Blinks	DTC stored	SAE Code: U1170

CAUTION / NOTICE / HINT

HINT:

If any of CAN communication system DTCs and sensor malfunction DTCs related to the CAN communication system are output simultaneously, perform troubleshooting for the CAN communication system DTCs first, then for the sensor malfunction DTCs.

PROCEDURE

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Stop and Start > Clear DTCs

2.	CHECK DTC OUTPUT

(a) Turn the ignition switch off and wait for 30 seconds or more.

(b) Start the engine.

(d) Read the DTCs.

Powertrain > Stop and Start > Trouble Codes

Result	Proceed to
DTC U010087, U012687, U012987, U013187, U014087, U015187, U015587, U016487 or U11087 is output	A
DTC U010087, U012687, U012987, U013187, U014087, U015187, U015587, U016487 or U11087 is not output	B

GO TO CAN COMMUNICATION SYSTEM

USE SIMULATION METHOD TO CHECK

External BBC Circuit (P33B300)

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