blazer immobiliser/security problem

[maceanruig]

Guys,
I live in Scotland and have an imported Blazer LT registered here in 1999. It is a 4.3 litre, sorry I don't know that in cubic inches, a Vortec? engineV6 automatic.
The car is fitted with a factory fitted engine immobiliser which has been playing up and now is doing its job too well, the car is well and truly immobilised, the engine won't turn over! All of the other functions work ok, central locking etc. The security light operates as it should etc. I'm looking for info. on the security system but can't get any when I try through dealers websites.
HELP!!!

[MT-2500]

Welcome to your first post on AF.
Have you got the pellet in the key or new style key?
Any horn blowing or lights flashing?
The anti theft normally just shuts down injectors not the starter.
If starter does not turn the engine it does not sound like anti theft.
Try the leave key on for 20 minutes and see what it does.
MT

[maceanruig]

Hi MT,
THanks for your response. I don't know about the pellet in the key, I take it you mean a transponder in the key? I have two keys and tried both but neither worked.
But just to let you know how the system works, the immobiliser fob has 4 buttons:
Open - press once to open drivers door only- indicators flash several times
press twice to open all doors
Lock - press once to lock all doors - indicators flash once
press twice to set alarm - horn sounds once to confirm
Tailgate - press once to open tailgate when doors other than drivers are
locked.
Panic button - to sound alarm.

Note when car unlocked - if not started within about 30 seconds, you have to relock then unlock to start. Also when not unlocked the immobiliser prevents the engine from turning over.
There is no power to the starter so I put a direct feed to the starter and the engine fired but immediately died no fuel, so the immobiliser prevents power to the starter and fuel to the injectors.
What I'm really looking for is a wiring diagram or schematic or any details of the immobiliser system, or even where in GM I could get this info.
Once again, thanks for any help you can give.
John

[MT-2500]

Originally Posted by maceanruig

Hi MT,
THanks for your response. I don't know about the pellet in the key, I take it you mean a transponder in the key? I have two keys and tried both but neither worked.
But just to let you know how the system works, the immobiliser fob has 4 buttons:
Open - press once to open drivers door only- indicators flash several times
press twice to open all doors
Lock - press once to lock all doors - indicators flash once
press twice to set alarm - horn sounds once to confirm
Tailgate - press once to open tailgate when doors other than drivers are
locked.
Panic button - to sound alarm.

Note when car unlocked - if not started within about 30 seconds, you have to relock then unlock to start. Also when not unlocked the immobiliser prevents the engine from turning over.
There is no power to the starter so I put a direct feed to the starter and the engine fired but immediately died no fuel, so the immobiliser prevents power to the starter and fuel to the injectors.
What I'm really looking for is a wiring diagram or schematic or any details of the immobiliser system, or even where in GM I could get this info.
Once again, thanks for any help you can give.
John

The pellet in the key is the old system old style gm key. Passlock.
It sounds like you have the new style content anti theft.
If the anti theft is acting up there should be a code stored in body/engine VCM.
Can you get the codes checked/read out on it?


Here is a link to bulldog that may have some wiring or info on it.
www.bulldogsecurity.com

Or all repair info and wiring diagrams on it can be found in the all data DIY repair info online subscription. 24.95 US $ a year
Plastic card and 10 minutes and they can set you up with it. Link below.
http://www.alldata.com/products/diy/index.html

Is this a 98 or 99 model?
MT

[Southern Comfort]

If you want to purchase a cd on your blazer, check this web site out. I don't know if they'll ship it to Scotland or not, but it's worth a try.I have purchase several cd's from this company and they are the most thorough I have found. The cd contains all the info about your blazer, from bumper to bumper.
http://www.autorepairmanualcd.com/index.php
Look at the website and see if they can sell you a cd. I paid 25 US dollars for the CD, and it's worth my weight in gold.
SC

[maceanruig]

To MT and Southern Comfort,
Thanks for your help guys, I am currently in touch with the two orgs. you suggested and am waiting for their response.
Slainte!