Car will not start, immobilizer is on

GERGELY ZSOLT

MEMBER
2006 VOLKSWAGEN POLO
1.2L
4 CYL
2WD
MANUAL
139,000 MILES

Yesterday night was nothing wrong with it. In the evening I opened the plastic part of the key as I wanted to take out the battery and buy a new one, I put everything back (i put back the old battery) but today the car would not start and the immobilizer is now on and intermittent and the car does not start. I disconnected the battery but this did not solve the problem, also I tried turning the ignition on and off couple of times in a row but without any success. Is anyone who had the same trouble and could fix it? Any advice? I only have one key and is without fob (just a simple key without any buttons)i will leave a picture with the key.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Unfortunately we don't have a service manual on your specific vehicle because it is not offered here in the USA however, it sounds like a pretty common issue. Basically the way this system works is the key contains a code sequence that will match with the module. So if you have a key that is programmed to the vehicle you may just need to relearn it. Let's try to put the key in the ignition and turn it to on position for up to 30 minutes. Clearly turn the radio and HVAC system off because we don't want to drain the battery too much.

This should relearn the key to the module and allow it to start. If it doesn't then we need to hook up a scan tool and find out if there are codes and second to have a key programmed to the vehicle. Lastly I would suggest having two programmed so you always have a back up. Let me know if you have questions. Thanks

https://www.2carpros.com/articles/how-to-reset-a-security-system