Hello. I'm in the UK, and I've only had my Blazer (a year 2000 LT) for three days and already the security features are driving me crazy. The guy who sold it to me told me that I had to press the door open button on the fob to override the vehicle security immobiliser and then the vehicle would start on the turn of the key. You had to press the fob a few times in a few different places near the steering column before you heard the door locks 'click' and you could turn the ignition. I put this down to a weak battery in the fob, so I changedthe battery and cleaned the terminals in the foblast night (and then found that it wouldn't start at all, until I read the instructionsinside the fob about holding down both buttons for a few seconds until the system resets itself), but it's no better. Personally, I hate being at the mercy of all this electronic cr*p, so is there any way to bypassor disablethe security system? Alternately I would be prepared to live with it if anyone could suggest how I could make the system a bit more reliable. I had to sit there for about twenty seconds this morning pressing the button madly in all different places before the car recognised that I was there. Very infuriating when you're in a rush. Any advice would be much appreciated.
Cheers
Lee

 

First off, is it factory...?

 

Post a pic of your remote

 

Hi folks. Since my post yesterday I've had the fob apart andhavedone a bit of experimenting. Seems like there's nothing amiss with the security system on the car itself (touch wood), it's just the contacts on the fob. It seems that the rubber buttons are just that - i.e. rubber - so no wonderthey were notmaking the circuit where they touched the circuit board. Maybe they originally had some kind of contact on the bottom, but if so this has now worn away. I've got round it byglueing a tiny piece of kitchen foil on the bottom of each button so it makes the circuit when the button presses against the circuit board. Seems to work okay so far and it didn't cost anything! I like repairs like that!

Cheers
Lee

 

One of my fobs quit working...I took it apart, and it was all wet(like oily wet) inside. I have no idea how it happened! I cleaned it up with a Q-tip, put it back together, and that fixed it!

 

Lee Any progress. I am in same boat and car stranded in outer london. I am an electronics engineer. Been through all threads, got auto covers off. checked neutral switch, etc. can get starter to turn over but won't fire. the secondary aftermarket immob is off as led off and security is not lit on dash so gmc immob is off. you press fobs and doors open and close and security and aftermarket displays act as they should. just won't start. you walk away, leave it 24 hours and 9 times out of 10 starts. i really need the starter wiring schematics, couls someone send them to whp427@hotmail.com asap. i am going to collect it tomorrow... either by driving or aa but i live in edinburgh... yes that is 300 miles. i parked it at hotel for overnight stay and next morning nothing....aaaaarggggghhhh
i am told by the only dealer in the uk it needs a £300 ecu upgrade and its a common problem. I don't belive it. this is an old american v6. the starter is immobilsed by auto selector, key, immob. clearly with both immobs saying its off it appears to still be on. by shorting starter relay can turn it over, but somewhere else the spark is being immobilsed. i suspect this is probably only an elec ignition overide, may be fuel pump or injector unit too, but i bet its only elec ign. i took key fob apart. there are three wires to key one yellw one black other red. i checked voltage on each. black 0v, red 5v, yellow 10v when ign on. you discvonnect it and then you get a hard ecu immobiliser on shown on dash with security lit up. to clear it you need to plug it back in, and remove battery terminals, short cables together, re connect and wait 10 mins just as the factory book says so it appears to be working right. in my experience of key switches there are normally 3 wires. one shorted to another for ign on, one shorted momentarily when you go to the starter turn over point then when its starts it spring releases with engine running. also next to three wires there is a small encapsulated chip. i guess this is aftermarket. three wires go in and come out but what does it do. any ideas. have aa cover but hate being beaten...? thanks,
beers by post for any helpful ideas/info
brian

 

Congrats! you've located the "chip" & harness (OEM) which are activated by a "Hall effect" switch in the staked over area of the ignition switch. The magnet for activating the switch is located in the lock cylinder. There is a crib for making the security system "relearn" the code word provided by the chip posted on this board (it's worth having should you have to replace the switch...common failure...or should the system become bollixed & "forget" the code word.

 

ok. update. there 3 hours went through both reteach procedures several times, neither of them worked i got no acknowledgements and nothing changed- still won't start. when you say staked, i am not understanding that. i use a piece of metal to try to find magnetic area, and couldn't, mind you that might be problem.... there is nothing marked on the column to show where hall effect switch should be. could you copy me your working lelearn crib. the one off the forum here door unlock ign on off on off etc don't work. neither does the 30 minute reset or the manual code in via fog light routine. have ordered new lock and barrel but not confident it will relearn. could i just try a bloody big magnet next to transponder bit? i really appreciate all help. car is on its way to me on low loader. bloody pain in the ****....