I've a lovely limited edition 2001 RHD UK Blazer.

It has not been run for 18 months as sat at the garage since the only key to deactivate the immobilser broke (circuits all knackered in key fob). The garage have stripped it out inside the dashboard, sent the key away to UK specialists, tried reprogramming and cannot remove the immobiliser - hence cannot start.

They now say the only option is to buy another Blazer(!) and cannibalize the parts.

Sure there is another way - like buying the parts from a scrapper.

What do I need to get the immobiliser removed? What parts are required?

Thank you!

 

Immobilizer? Are you referring to the built-in security system? Or are you referring to a system that was later added to the truck?

If it is the original built-in system, perhaps someone has the schematics of the security system they can post for you. I have them in 1999 service manual but there is no certainty that they would be the same.

 

Before going too deep down the security rabbit hole, when you're trying to start the truck (cranking the engine) is the security light flashing? If it is not, then the no-start situation is likely not related to the factory Passlock system. If your truck has a different security system then please disregard this as I have no idea how it would normally behave.

I don't know if the UK version of the Blazers used a different security system, but in North America all 1998-2005 Blazers and other S-series trucks used the GM Passlock-2 system, which is a resistance based lock cylinder security system where the resistance from the lock cylinder is read by the BCM and allows or prevents the vehicle from starting. The key itself does not have any transponder, and can be replaced with any blank key cut to match the lock cylinder. With the Passlock system, you can bypass it with a simple resistor of the correct value for the truck placed in-line on the Passlock wires from the lock cylinder, with the caveat that inexpensive resistors can change resistance value over time as they age from use, which may eventually lead to the security system causing a no-start situation again in the future. that being said, I used a resistor to bypass the Passlock system for my remote-starter for 8 years without any troubles. Your experience may be different than mine.

 

Just my 2 cents worth, not trying to step on any toes, just help. I remenber years ago. I had a similar problem security light coming on. I replaced the cylinder lock key. It didn't solve it. I also had no communication at dlc. So I couldn't pass n.h. emissions. I traced it back to 2 loose ground stud nuts pretty loose. Located on left half of firewall half to three quarter ways up from floor. They're not easy to get to. But I tightened both and security lights has been out since. I also got dlc back too. Hope this helps!