B3935
Transponder Authentication
B3935 is an OBD-II diagnostic trouble code meaning: Transponder Authentication. Common causes: damaged key with transponder, immobilizer antenna malfunction. Estimated repair cost: $33–167.
Symptoms
- Engine won't start
- The immobilizer indicator is flashing
- The car does not respond to the key
Causes
- Damaged key with transponder
- Immobilizer antenna malfunction
- Problems with the immobilizer control unit
- Software failure
- Unauthorized key
How to Fix
- Check the key for damage
- Diagnose the immobilizer antenna
- Read errors in the immobilizer control unit
- Reprogram or replace the key
- If necessary, replace the control unit
Related codes
Error B3935 by Vehicle Brand
FAQ
What does the B3935 code mean?
B3935 is an OBD-II diagnostic trouble code that indicates: Transponder Authentication
What causes a B3935 error code?
The most common causes of B3935 include: Damaged key with transponder; Immobilizer antenna malfunction; Problems with the immobilizer control unit; Software failure.
How do I fix a B3935 diagnostic trouble code?
To fix B3935: Check the key for damage. Diagnose the immobilizer antenna. Read errors in the immobilizer control unit. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with B3935?
Yes, but get it checked soon
How much does it cost to fix B3935?
The estimated repair cost for B3935 is $33–167. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat