Problem: The Chevrolet Tahoe 2005 5.3 Liter has a fault code B3031 “Security system control in learn mode” on Autel IM608 II. The car is running normally but the immobilizer light is on.
What’s the matter? Please help.
AutelShop.DE engineer replied
The vehicle should still be in learning mode.
Power off the vehicle for 5 mins, then connect it to see if the problem was solved.
Update
Hello my friend, I removed the battery and connected it. After 10 minutes, the car started without any lights appearing on the dashboard. After a 5 minute, however, when I turned off the engine and took the key, I tried after a while and the car started normal , but the anti-theft light appeared again.
AutelShop.DE engineer replied
DTC B3031 – Security System Controller in learning mode usually means that the vehicle’s anti-theft system (Passlock, Passkey, or imburglar) is in a relearning state or is unable to correctly identify the key. This is more common in Chevrolet cars and usually occurs when a disconnected battery or key, ignition switch, body control module (BCM) fails.
Possible Reasons:
- Battery power failure or low voltage – If the battery has been disconnected recently, the anti-theft system may need to re-learn.
- Key or anti-theft chip malfunction – the key’s chip may not be properly identified.
- Ignition lock or Passlock sensor problems – Aged or damaged ignition lock may affect identification.
- Body Control Module (BCM) failure – The BCM is responsible for managing the anti-theft system and if something goes wrong, the system may not work properly.
Solution (How to fix B3031)
- Passlock relearning procedure (manual learning)
If the vehicle does not recognize the keys properly, follow these steps:
- Insert the key and turn it to the “ON” (power on) position (but do not start the engine).
- Keep it in this state for 10-15 minutes until the anti-theft light goes off or stops flashing.
- Turn OFF the key (OFF) and wait 30 seconds.
- Repeat the above steps 1-3 twice (a total of 3 cycles, about 30-45 minutes).
- After the third time, turn off the key again, wait 30 seconds, and then try to start the car.
- Disconnect the battery and reset the system
Disconnect the negative battery terminal.
Wait at least 30 minutes.
Reconnect the battery and try to start the car.
If the problem persists, try Passlock to relearn the program.
- Check possible faulty components
Keys: If you have a spare key, try to start the car with the spare key.
Ignition lock cartridge: may need to be replaced if aged or damaged.
Line connection: Check the line associated with the Passlock sensor for damage or poor contact.
- Use the OBD2 diagnostic device to clear the fault code
If the problem is intermittent, try reading and clearing the trouble code with an OBD2 diagnostic tool like Autel IM608 PRO2 to see if it reappears.
If the problem persists:
If none of the above methods work, you may need to:
- Deep diagnosis and system re-learning with the GM Tech 2 diagnostic instrument.
- Go to a 4S shop or a professional auto locksmith to reprogram the keys and anti-theft system.
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