Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJJS
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM(for Start Function): U0100; Lost Communication with ECM / PCM; 2016 - 2020 MY Sienna [12/2015 -        ]

DTC

U0100

Lost Communication with ECM / PCM

DESCRIPTION

This DTC is stored when a malfunction in the CAN communication between the power management control ECU and ECM is detected.

HINT:

  • When the power management control ECU is replaced with a new one and the cable is connected to the negative (-) battery terminal, the power source mode changes to on (IG).
  • When the battery cable is disconnected and reconnected, the power source returns to the mode it was in before the battery cable was disconnected.

DTC Code

DTC Detection Condition

Trouble Area

DTC Output Confirmation Operation

U0100

CAN communication malfunction between the power management control ECU and ECM (1-trip detection logic*).

  • CAN communication system
  • Power management control ECU

Wait 4 seconds or more after turning the engine switch on (IG).

  • *: Only output while a malfunction is present and the engine switch is on (IG)

Vehicle Condition and Fail-safe Function when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Function when Malfunction Detected

No effect on vehicle behavior.

CAN communication is normal and the engine speed signal from the direct line is abnormal:

  • If the engine switch is pressed briefly, cranking stops when the starter OFF permission flag is received via CAN communication.
  • If the engine switch is pressed and held, cranking stops according to the engine speed signal sent via CAN communication.

CAN communication is abnormal and the engine speed signal from the direct line is normal:

  • If the engine switch is pressed briefly, cranking stops according to the engine speed signal from the direct line.
  • If the engine switch is pressed and held, cranking stops according to the engine speed signal from the direct line.

Both CAN communication and the engine speed signal from the direct line are abnormal:

  • If the engine switch is pressed briefly, cranking stops after 6 seconds elapse.
  • If the engine switch is pressed and held, cranking is maintained for a maximum of 30 seconds.

CAUTION / NOTICE / HINT

NOTICE:

  • When using the Techstream with the engine switch off, perform either of the following: 1) Turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and vehicle begins, or 2) connect the Techstream to the vehicle, select the vehicle type under manual mode, and then enter the following menus: Body Electrical / Smart Key / Trouble Codes.
  • The smart key system uses multiplex communication. First perform the inspections in "How to Proceed with Troubleshooting" to confirm that there are no communication malfunctions before proceeding with troubleshooting (See page 2016 MY Sienna [12/2015 - 08/2016]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2018 - 2020 MY Sienna [11/2017 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING ).
  • Inspect the fuses of circuits related to this system before performing the following inspection procedure.
  • After performing repairs, perform the operation that fulfills the DTC output confirmation operation, and then confirm that no DTCs are output again.

Related Data List and Active Test Items

DTC

Data List Item

Active Test Item

U0100

-

-

PROCEDURE

1.

CHECK FOR DTC

(a) Record any output DTCs (See page 2016 - 2020 MY Sienna [12/2015 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM(for Start Function): DTC CHECK / CLEAR ).

NOTICE:

  • When using the Techstream with the engine switch off, perform either of the following: 1) Turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and vehicle begins, or 2) connect the Techstream to the vehicle, select the vehicle type under manual mode, and then enter the following menus: Body Electrical / Smart Key / Trouble Codes.
  • The smart key system uses multiplex communication. First perform the inspections in "How to Proceed with Troubleshooting" to confirm that there are no communication malfunctions before proceeding with troubleshooting (See page 2016 MY Sienna [12/2015 - 08/2016]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2018 - 2020 MY Sienna [11/2017 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING ).
NEXT

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

(See page 2016 MY Sienna [12/2015 - 08/2016]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2018 - 2020 MY Sienna [11/2017 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING )