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Home >> Toyota >> 2025 >> Land Cruiser Base >> Repair and Diagnosis (Single Page) >> Body & Frame >> Door Locks >> Smart Key System (For Start) - Diagnostic Codes (2 Of 2) & Symptom Tests >> SMART KEY SYSTEM (for Start Function) >> DTC U0100-87: Lost Communication With ECM/PCM "A" Missing Message; DTC U0103-87: Lost Communication with Gear Shift Control Module "A" Missing Message; DTC U0129-87: Lost Communication with Brake System Control Module "A" Missing Message; DTC U0140-87: Lost Communication with Body Control Module Missing Message; DTC U0155-87: Lost Communication with Instrument Panel Cluster (IPC) Control Module; DTC U0230-87: Lost Communication with Rear Gate Module Missing Message; DTC U1117-87: Lost Communication with Accessory Gateway Missing Message [02/2024 - ] >> Description
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DTC U0100-87: Lost Communication With ECM/PCM "A" Missing Message; DTC U0103-87: Lost Communication with Gear Shift Control Module "A" Missing Message; DTC U0129-87: Lost Communication with Brake System Control Module "A" Missing Message; DTC U0140-87: Lost Communication with Body Control Module Missing Message; DTC U0155-87: Lost Communication with Instrument Panel Cluster (IPC) Control Module; DTC U0230-87: Lost Communication with Rear Gate Module Missing Message; DTC U1117-87: Lost Communication with Accessory Gateway Missing Message [02/2024 - ]: Description

These DTCs are stored when a malfunction occurs in the CAN communication circuit.

DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from Priority Note
U0100-87 Lost Communication With ECM/PCM "A" Missing Message CAN communication malfunction between certification ECU (smart key ECU assembly) and ECM (1-trip detection logic*) ECM Smart Key
Power Source Control		 B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0103-87 Lost Communication with Gear Shift Control Module "A" Missing Message CAN communication error between certification ECU (smart key ECU assembly) and shift control ECU (1-trip detection logic*) Shift control ECU Power Source Control B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0129-87 Lost Communication with Brake System Control Module "A" Missing Message CAN communication error between certification ECU (smart key ECU assembly) and No. 2 skid control ECU (brake actuator assembly) (1-trip detection logic*) No. 2 skid control ECU (brake actuator assembly) Smart Key
Power Source Control		 B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0140-87 Lost Communication with Body Control Module Missing Message CAN communication malfunction between certification ECU (smart key ECU assembly) and main body ECU (multiplex network body ECU) (1-trip detection logic*) Main body ECU (multiplex network body ECU) Smart Key
Power Source Control		 B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0155-87 Lost Communication with Instrument Panel Cluster (IPC) Control Module CAN communication malfunction between certification ECU (smart key ECU assembly) and combination meter assembly (1-trip detection logic*) Combination meter assembly Smart Key
Power Source Control		 B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U0230-87 Lost Communication with Rear Gate Module Missing Message CAN communication malfunction between certification ECU (smart key ECU assembly) and outer mirror control ECU assembly (1-trip detection logic*) Outer mirror control ECU assembly Smart Key B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
U1117-87 Lost Communication with Accessory Gateway Missing Message CAN communication malfunction between the certification ECU (smart key ECU assembly) and the option connector (bus buffer ECU) for approximately 10 seconds or more. Option connector (bus buffer ECU) Smart Key
Power Source Control		 B DTC Output Confirmation Operation: 
  1. Turn the ignition switch to ON and wait at least 10 seconds.
  1. *: Only detected while a malfunction is present.
VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

DTC Code Vehicle Condition when Malfunction Detected Fail-safe Function when Malfunction Detected
U0100-87 The vehicle power source mode cannot be turned off by the automatic P position function. (it is possible for the power source to be turned off by manually selecting the P position) 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 power 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 power 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 power switch is pressed, the engine stops cranking after 6 seconds.
  • When the power switch is pressed and held, the engine remains cranking for up to 30 seconds.
U0103-87 There is no effect on vehicle behavior. -
U0129-87 There is no effect on vehicle behavior. -
U0140-87
  • Doors cannot be locked or unlocked.
  • The warning (wireless buzzer) does not sound.
 -
U0155-87 The warning (meter buzzer) does not sound and no warning messages displayed on the multi-information display. -
U0230-87 Power back door system does not operate. -
U1117-87 The engine cannot be started using the wireless remote control function. -
RELATED DATA LIST AND ACTIVE TEST ITEMS

DTC No. Data List and Active Test
U0100-87
U0103-87
U0129-87
U0140-87
U0155-87
U0230-87
U1103-87
U1117-87		 -
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