B3935

DTC B3935

CIRCUIT DESCRIPTION
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 control module. The theft deterrent control module then compares this value to a value stored in memory, learned key code. If the value is correct, the theft deterrent control module sends a random generated number to the transponder; this is called a challenge. Both the transponder and the theft deterrent control module perform a calculation on the challenge. If the calculations match, the theft deterrent control module sends the fuel enable password via the serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect, the theft deterrent control module will send the fuel disable password to the ECM, via the serial data circuit.

DTC DESCRIPTOR




This diagnostic procedure supports the following DTC:
DTC B3935 Transponder Authentication Error

This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description. DTC Symptom Description

CONDITIONS FOR RUNNING THE DTC
The ignition switch is in the ACC or Run position and the battery voltage is greater than 9 volts.

CONDITIONS FOR SETTING THE DTC
- The transponder value matches the value stored in the theft deterrent control modules memory.
- The transponders calculation on the challenge from the theft deterrent control module does not match the theft deterrent control modules calculation.

ACTION TAKEN WHEN THE DTC SETS
- The vehicle will not start.
- The security indicator will flash.

CONDITIONS FOR CLEARING THE MIL/DTC
- The theft deterrent control module clears the current status of the DTC when the transponders calculation on the challenge matches the theft deterrent control modules calculation.
- A history DTC will be cleared after 100 malfunction-free ignition cycles.
- The DTC can be cleared by using a scan tool.

TEST DESCRIPTION

Step 1 - Step 6:

The numbers below refer to the step numbers on the diagnostic table:
2. This step verifies that the conditions for setting DTC B3055 or B3060 are not current.
3. If a new key must be tried, the key must have the proper mechanical cut and the theft deterrent control module must "learn" the transponder value.
4. If the replacement key does not work, the theft deterrent control module must be malfunctioning.