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Home >> Lexus >> 2019 >> UX 250h Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Smart Access System W/ Push-Button Start (Start Function) (Diagnostic Codes & Symptom Tests (1 Of 2)) (Hybrid) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function, HV Model) >> DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [10/2018 - ] >> Description
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DTC B2799-86: Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid [10/2018 - ]: Description

If there is a communication malfunction between the hybrid vehicle control ECU and ID code box (immobiliser code ECU), or when the communication ID codes do not match, the hybrid vehicle control ECU stores this DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area Note
B279986 Engine Immobiliser System Signal (Some Circuit Quantity, Reported via Serial Data) Invalid Either of the following conditions is met (1 trip detection logic*):
  • A malfunction is detected in the communication or communication lines between the hybrid vehicle control ECU and ID code box (immobiliser code ECU).
  • The communication ID codes of the hybrid vehicle control ECU and ID code box (immobiliser code ECU) do not match.
  • ID code box (immobiliser code ECU)
  • Hybrid vehicle control ECU
  • Wire harness or connector
DTC output confirmation operation (Perform either of the following):
  • Start the hybrid control system and wait for 10 seconds. If there is a malfunction, the hybrid control system will stop (communication begins within 3 seconds of the hybrid control system start operation being performed, and DTCs are stored after 6 seconds).
  • Connect the cable to the negative (-) auxiliary battery terminal, start the hybrid control system and wait for 10 seconds (communication begins within 3 seconds of the power switch being turned on (IG), and DTCs are stored after 6 seconds).
  1. *: Only output while a malfunction is present.
VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
Hybrid control system cannot be started -
RELATED DATA LIST AND ACTIVE TEST

DTC No. Data List and Active Test
B279986 -