LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2020 >> UX 250h Luxury >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 5 (Smart Access System W/ Push-Button Start (Start Function) (Diagnostics - Introduction) (Except Hybrid)) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function, Gasoline Model) >> Problem Symptoms Table [10/2018 - 08/2021] >> Problem Symptoms Table [10/2018 - 08/2021]
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Problem Symptoms Table [10/2018 - 08/2021]

WARNING: This page is about a different car, the 2022 Lexus UX 200, 2021 Lexus UX 200, 2020 Lexus UX 200, and 2019 Lexus UX 200. However, it is still accessible from the selected car via links, so may be relevant.

HINT: 

SMART ACCESS SYSTEM WITH PUSH-BUTTON START (FOR START FUNCTION, ENGINE MODEL)

Symptom Suspected Area Link
Power source mode does not change to on (IG) or on (ACC) Smart access system with push-button start (for Entry Function, Engine Model) Refer to Power Source Mode does not Change to ON (IG and ACC) [10/2018 - 08/2021]
Wireless charging system*1
Affected by wave interference
Transmitter battery
Electrical key transmitter sub-assembly
No. 1 indoor electrical key antenna assembly (front floor)
No. 3 indoor electrical key antenna assembly (rear floor)
No. 1 indoor electrical key antenna assembly (inside luggage compartment)
Engine switch
Wire harness or connector
Instrument panel junction block assembly
Certification ECU (Smart key ECU assembly)
Power source mode does not change to on (IG) Wire harness or connector Refer to Power Source Mode does not Change to ON (IG) [10/2018 - 07/2022]
Relay
Instrument panel junction block assembly
Certification ECU (Smart key ECU assembly)
Power source mode does not change to on (ACC) Wire harness or connector Refer to Power Source Mode does not Change to ON (ACC) [10/2018 - 07/2022]
Relay
Instrument panel junction block assembly
Certification ECU (Smart key ECU assembly)
Engine does not start SFI system Refer to Engine does not Start [10/2018 - 07/2022]
Immobiliser function
Steering lock function
Wire harness or connector
Shift lock control unit assembly
Stop light switch assembly
Certification ECU (Smart key ECU assembly)
New key cannot be registered LIN communication system Refer to New Key cannot be Registered [10/2018 - 07/2022]
Meter / gauge system
Reregistration
Electrical key transmitter sub-assembly
Steering lock ECU (Steering lock actuator or upper bracket assembly)
ID code box (Immobiliser code ECU)
Certification ECU (Smart key ECU assembly)
Additional key cannot be registered Steering lock function Refer to Additional Key cannot be Registered [10/2018 - 07/2022]
Electrical key transmitter sub-assembly
Certification ECU (Smart key ECU assembly)
New key registration warning message is not displayed Lighting system (int) Refer to New Key Registration Warning Message is not Displayed [10/2018 - 07/2022]
Meter / gauge system
Certification ECU (Smart key ECU assembly)
"Key Battery Low Replace Key Battery" is Displayed on the Multi-information Display Transmitter Battery Refer to "Key Battery Low Replace Key Battery" is Displayed on the Multi-information Display [10/2018 - 07/2022]
Unable to unlock steering wheel (engine cannot start) Wire harness or connector Refer to Unable to Unlock Steering Wheel (Engine cannot Start) [10/2018 - 07/2022]
Steering lock ECU (Steering lock actuator or upper bracket assembly)
ID code box (Immobiliser code ECU)
Certification ECU (Smart key ECU assembly)
Steering lock does not lock Lighting system (int) Refer to Steering Lock does not Lock [10/2018 - 07/2022]
Wire harness or connector
Steering lock ECU (Steering lock actuator or upper bracket assembly)
ID code box (Immobiliser code ECU)
Certification ECU (Smart key ECU assembly)
Security indicator light does not blink Wire harness or connector Refer to Security Indicator Light Does not Blink [10/2018 - 07/2022]
Security indicator light (Air conditioning control assembly)
Main body ECU (Multiplex network body ECU)
Certification ECU (Smart key ECU assembly)
Immobiliser system does not operate properly Communication ID registration was defective Refer to Immobiliser System does not Operate Properly [10/2018 - 07/2022]
Wire harness or connector
ID code box (Immobiliser code ECU)
ECM
Engine cannot be started by remote engine start and stop (Both the wireless door lock control system and push-button start function operate normally)*2 Refer to "Remote Engine Starter does not Operate" Refer to Remote Engine Starter does not Operate [10/2018 - 10/2019] , or refer to Remote Engine Starter does not Operate [10/2019 - 07/2022]
Engine switch illumination does not illuminate or blink
(Engine switch lettering illumination indication function does not operate)
Engine switch illumination circuit Refer to Engine Switch Illumination Circuit [10/2018 - 07/2022]
Certification ECU (Smart key ECU assembly) -
  1. *1: w/ Wireless Charging System
  2. *2: for Lexus Enform