left work (well tried to) got in the car, started it...it ran for about 10 seconds and died. Started it again, ran for 10 seconds, died. Now it wont start again. Towed it to my mechanic. He suspected Fuel Pump, tested pressure, it's ok. He's not getting and OBDII Codes from the computer. It's getting fire (tested by grounding). Now I'm looking at possibly replacing ecu (Computer)...but my problem is I can't get a straight answer from anyone on how this will affect the key/immobilizer/computer.
I've been told that the immobilizer and computer are a pair, if I get a salvage I have to get both. And even then the dealership will have to reprogram my keys.
How does this key/immobilizer/ecu system work. And what would be the cheapest way to fix my problem if it ends up being the ecu? (Mechanic is replacing the coil pack first to see if that fixes it)

 

First thing we need to determine is if the immobilizer system is causing the engine to stall or if it is entirely unrelated. Need to know what the immobilizer security light is doing when you turn the key to 'run'position. This is the one that looks like the outline of a car with a key in it. Does it illuminate and then turn off, flashing rapidly, or just stays on solid?? How many keys to you have??
The system works by comparing ID signals and code words between key, immobilizer unit and PCM. Everybody has to match or will not keep running. Below is a system description outline.

[IMG]local://upfiles/1377/207408AED3FF4E2FBB8DE1C317203778.gif[/IMG]

Sorry that did not come out very good. Had to crank the resolution on monitor up and then could read it ok.

 

thanks a ton for the info, mechanic swapped coils and it fired up, then put my old coil back in (suspecting faulty wiring, bad ground, etc) and it fired up...so i drove it home and it is doing it again. start 3x die, then no start. I'll run thru the flow chart and post results this weekend. My next question is what if the security light stays on or is flashing...is it a new immobilizer or key? or just a reset thing? How does one re-sync these devices?

 

have 2 keys....mechanic had one (B)....got it firing off it when he played w/ the coil and when I picked it up I started it with the other one (A)...drove home, tried to start w/ my (A) key and it wouldn't start...tried (B) key & still wouldn't start.

 

2000 626 ES V6 if that helps...

 

K, went to repair shop...they won't let me touch it but I had to get some things out of my car and I played for a minute.
I put key (B) in...
Turned to 'ON' position...CEL, Batt lights on, no immob sec light at all...
Tried key (A) same thing...
Turned key off/on 10x fast, immob light illuminated, after about 30 seconds it cleared...*Did this w/ both keys...same result

 

What coil??? The ignition coil that produces spark for the spark plugs or the immobilizer coil around the ignition switch?
Sounds like you definitely have an immobilzer related fault as it will start three times and then not at all. Rapidly flashing security light usually indicates a fault in the key itself. Light remaining on is typically a Code Word missmatch fault.
There is a self diagnositic mode that will flash you a code when a fault is detected in the system. To enter diagnostic mode turn the ignition key to the "START" position for 2 seconds then release key back to the "RUN" position. Wait for 2 minutes and the security light should (hopefully) start flashing and output a code to tell you what the problem is. There are 7 different code numbers that can be output. 1, 2, 3, 11, 21, 24, and 30. The flashes may be different in duration so attention must be paid to the amount of time light is on when flashing. Long flashes are a tens digit. Short flashes are a ones digit. (ie Three short flashes, pause, Three short flashes, pause, etc would be a code 3. Two long flashes the four short flashes, pause, Two long flashes and four short flashes, etc would be a code 24). The 3 and 30 might throw you as you will not know if that is a short or long flash. Just remember that a short flash will be approx 300 miliseconds in duration, long flash will be 1.2 seconds in duration. See if the system will output a code and give us a better direction if you can.

 

K, here's the latest...
after my trials today, I had it towed to another mechanic (I wasn't getting a nice feel from the other one) after the tow, it started fine. And is starting again and again.

 

Hmmmm. Might still be able to get a code out. Does not say if it only stores code when problem is happening or not but would be worth a shot. Think I would be looking at the electrical connections to the system components and make sure they are solidly connected and do not have one just barely making contact. Not much in the system. Imobilizer unit is a small black box located straight up from drivers footwell, connector only has seven wires too it. Key coil is around the ignition key cylinder with only two wires to it. If you follow the key coil a short ways there is one other connection and that is pretty much it for the system. Almost has to be something like that for it to work fine and then suddenly lock up.

 

Sweet, I'm gonna give it a go...heading to mechanics shop now... Thanks! I'll update the post when I get back.