WHAT IS 2006 chevrolet malibu CODE B3935 - Chevrolet Cars & Trucks

It's a security code for your transponder in your key that match the switch. Have you had a new key cut lately ? You can take it to the dealer or a local Locksmith that does ignition switch work. Your switch may have gone bad . And the locksmith should be cheaper.

B3935
Transponder Authentication Error
TDM
DTC B3935

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the theft deterrent module (TDM). The TDM then compares this value to a value stored in memory, learned key code. If the value is correct, the TDM sends a random generated number to the transponder. This is called a challenge. Both the transponder and the TDM perform a calculation on the challenge. If the calculations match, the TDM sends the fuel enable password via the serial data circuit to the powertrain control module (PCM). If either the transponders unique value or the calculation to the challenge is incorrect, the TDM will send the fuel disable password to the PCM via the serial data circuit.