DSD Information System
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Smart Key System (For Start, Except HV) - Diagnostic Codes (2 Of 2) & Symptom Tests (1 Of 2) >> SMART KEY SYSTEM (for Start Function, Gasoline Model) >> DTC U0100: Lost Communication with ECM / PCM; DTC U0140: Lost Communication with Main Body ECU; DTC U0142: Lost Communication with Main Body ECU; DTC U0155: Lost Communication with Combination Meter [12/2019 - 10/2021] >> Description

DTC U0100: Lost Communication with ECM / PCM; DTC U0140: Lost Communication with Main Body ECU; DTC U0142: Lost Communication with Main Body ECU; DTC U0155: Lost Communication with Combination Meter [12/2019 - 10/2021]: Description

These DTCs are stored when there is a CAN communication malfunction between the certification ECU (smart key ECU assembly), ECM, main body ECU (multiplex network body ECU), combination meter assembly or engine stop and start ECU*.

  1. *: w/ Stop and Start System
DTC No. Detection Item DTC Detection Condition Trouble Area Note
U0100 Lost Communication with ECM / PCM CAN communication malfunction between certification ECU (smart key ECU assembly) and ECM (1-trip detection logic*1) ECM DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0140 Lost Communication with Main Body ECU CAN communication malfunction between certification ECU (smart key ECU assembly) and main body ECU (multiplex network body ECU) (1-trip detection logic*1) Main body ECU (multiplex network body ECU) DTC Output Confirmation Operation: 
  1. Always
U0142 Lost Communication with Main Body ECU CAN communication malfunction between certification ECU (smart key ECU assembly) and main body ECU (multiplex network body ECU) (1-trip detection logic*1) Main body ECU (multiplex network body ECU) DTC Output Confirmation Operation: 
  1. Always
U0155 Lost Communication with Combination Meter CAN communication malfunction between certification ECU (smart key ECU assembly) and combination meter assembly (1-trip detection logic*1) Combination meter assembly DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
  1. *1: Only detected while a malfunction is present.
  2. *2: w/ Stop and Start System
VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

DTC Code Vehicle Condition when Malfunction Detected Fail-safe Function when Malfunction Detected
U0100 There is no effect on vehicle behavior. If the following conditions are met, it can be determined that the malfunction is not in the direct line (NE) but in the CAN communication system.
  • When the engine switch is pressed, the system controls the engine based on the engine speed signal via direct line, causing the engine to stop cranking.
  • When the engine switch is pressed and held, the system controls the engine based on the engine speed signal via direct line, causing the engine to stop cranking.

If the following conditions are met, it can be determined that there is a malfunction in both the CAN communication system and the direct line (NE).

  • When the engine switch is pressed, the engine stops cranking after 6 seconds.
  • When the engine switch is pressed and held, the engine remains cranking for up to 30 seconds.
U0140
U0142
  • Doors cannot be locked or unlocked.
  • The warning (wireless buzzer) does not sound.
 -
U0155 The warning (meter buzzer) does not sound and no warning messages displayed on the multi-information display. -
U1103*
  • When idling is stopped by the stop and start system, the ECM misjudges it as an engine stall.
  • While the engine stopped by the stop and start system, the immobilizer function is set due to a door operation.
 -
  1. *: w/ Stop and Start System
RELATED DATA LIST AND ACTIVE TEST ITEMS

DTC No. Data List and Active Test
U0100
U0140
U0142
U0155
U1103*		 -
  1. *: w/ Stop and Start System
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