Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B2271: Ignition Hold Monitor Malfunction [11/2018 - ]: Procedure
- CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
- Measure the voltage according to the value(s) in the table below.
*a Component with harness connected
(Certification ECU (Smart Key ECU Assembly))Standard Voltage
Tester Connection Switch Condition Specified Condition G54-17 (IG1D) - Body ground Power switch on (ACC) → Power switch on (IG) 1 V or less → 9 V or higher Result
Proceed to OK NG
Result:
OK
END (TEMPORARY CONNECTION FAILURE IS SUSPECTED). Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ]
Result:
NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [11/2018 - 02/2019] , or refer to REMOVAL [02/2019 - 10/2019] , or refer to REMOVAL [10/2019 - 08/2020] , or refer to REMOVAL [08/2020 - 12/2021] , or refer to REMOVAL [12/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
- Measure the voltage according to the value(s) in the table below.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.