DTC U0100-87: Lost Communication with ECM/PCM "A" Missing Message; DTC U0101-87: Lost Communication with TCM Missing Message; DTC U0129-87: Lost Communication With Brake System Control Module Missing Message; DTC U0140-87: Lost Communication with Body Control Module Missing Message; DTC U0151-87: Lost Communication with Restraints Control Module Missing Message; DTC U0155-87: Lost Communication with Instrument Panel Cluster (IPC) Control Module Missing Message; DTC U0164-87: Lost Communication with HVAC Control Module Missing Message; DTC U115C-87: Lost Communication with ECM/PCM "A" (ch5) Missing Message; DTC U1170-87: Lost Communication with Brake System Control Module (ch2) Missing Message [11/2023 - ]: Description

The engine stop and start ECU communicates with the engine control system, electronically control brake 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 P323A-16.
• 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 vehicle control history code X087A.

  e.g.: When the backup boost converter (built into the engine stop and start ECU) detects overcurrent in the power source circuit of the steering sensor and cuts off power supply, the engine stop and start ECU stores vehicle control history code X087A.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	Note
U0100-87	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	Does not come on	Does not come on	SAE Code: U0100
U0101-87	Lost Communication with TCM Missing Message	No communication between the engine stop and start ECU and TCM for 10.84 seconds.	Wire harness or connector Engine stop and start ECU TCM	Comes on	Does not come on	SAE Code: U0101
U0129-87	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)	Comes on	Does not come on	SAE Code: U0129
U0140-87	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)	Does not come on	Does not come on	SAE Code: U0140
U0151-87	Lost Communication with Restraints Control Module Missing Message	No communication between the engine stop and start ECU and airbag ECU assembly for 10.6 seconds.	Wire harness or connector Engine stop and start ECU Airbag ECU assembly	Does not come on	Does not come on	SAE Code: U0151
U0155-87	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 10.6 seconds.	Wire harness or connector Engine stop and start ECU Combination meter assembly	Does not come on	Blinks	SAE Code: U0155
U0164-87	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	Does not come on	Does not come on	SAE Code: U0164
U115C-87	Lost Communication with ECM/PCM "A" (ch5) Missing Message	No communication between the engine stop and start ECU and ECM for 10.6 second.	Wire harness or connector Engine stop and start ECU ECM	Comes on	Does not come on	SAE Code: U115C
U1170-87	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 2.22 second	Wire harness or connector Engine stop and start ECU Skid control ECU (brake actuator assembly)	Does not come on	Blinks	SAE Code: U1170