B3935

Transponder Authentication

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$33–167 (est.)

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

B3936 B3937 P0513