B2794 Unmatched encryption code in the immobilizer system
What does B2794 mean on a Toyota?
B2794. Unmatched encryption code in the immobilizer system. The key chip and the certification ECU do not share a valid code. This Toyota-enhanced code applies to Toyota, Lexus and Scion models that use this code.
Common causes of B2794
- Key not registered to the vehicle
- Faulty key transponder chip
- Faulty certification ECU
- Corroded engine switch connector
- Interrupted key registration
How to fix B2794
- Confirm the code with a scan tool
- Try a known good registered key
- Re-register the key to the vehicle
- Inspect and reseat the engine switch connector
- Replace the ECU only after tests fail