1990 DeVille not starting

[pithi69]

Okay so how is everyone? My car is a 1990 4.5 it has been sitting for the winter but I would start it everyone now and then and it would start fine. Now the sun's out and it would be nice to drive, if the car would start. Everything works when I turn the key, lights, horn, stereo, etc. But the car itself will just not turnover.

At first I read that if the car has been sitting for awhile the starter relay will take awhile to kick in and to wait 30 seconds with the key on before starting the car. This worked for the first 2 or 3 times but not anymore. So I thought, bad starter relay. I changed that, still same thing.

I checked the battery and the starter, both are good. I even bought a refurbished starter and installed it, still nothing. The starter is getting 12V at the constant but no voltage at the purple igntion wire. I was getting trouble codes F30 and F31. (F30 Climate control panel to Body Control Module (BCM) data problem) (F31 Fuel data center to BCM data problem) But these codes disappeared after I reset them.

I read on previous threads for a similar problem that it might be the Ignition Control Module. I changed that aswell and still same problem. Now there's a code E52 which I believe is 'PCM/ECM Memory Reset.'

I have even removed the steering wheel and checked the two small white wires coming from the ignition and they seem fine as well. No broken wires or anything. I have also tried to start it in neutral saying the neutral saftey switch is bad, but still no go.

The last thing that comes to mind is the Anti-Theft Deturrent system the VATS system or whatever it might be that GM installed in this car. I know that you can by-pass it using a relay and the proper resistance (which I don't know how to figure out).

Does anybody know the answer!!! I need help!! Could it be the VATS system, or a bad BCM? Or something else?? The last resort will be a mechanic which will probably over charge and it is an old car so would be no point. I do not know what else to do, I love the car!

Please help!! Thanks!

[maxwedge]

From here it is impossible to determine the cause , does the security lite stay on, if so the vats is the issue. You could measure the resistance of the key chip, go to Radio Shack make up a resistor to match the key, trace the wires to the bottom of the column from the key cylinder, jump the resistor into the body side of the connector.

[MagicRat]

Originally Posted by maxwedge

From here it is impossible to determine the cause , does the security lite stay on, if so the vats is the issue. You could measure the resistance of the key chip, go to Radio Shack make up a resistor to match the key, trace the wires to the bottom of the column from the key cylinder, jump the resistor into the body side of the connector.

Look here for a procedure. While this applies to a 1991 and later Caddy, it may help you

[maxwedge]

Nice link, way better than my " verbal" description.

[pithi69]

Hey Thanks for the replies guys! I will try this out and see if the problem is solved, if not....I DUNNO!! lol

[pithi69]

Ok well I did it and it still doesn't work. Are there more wires for the ignition besides just the two white ones in the column? A guy at the dealership said these cars are common for the ignition wires to get brittle and break.

[maxwedge]

There is nothing in the column at this point. You will need to check for current thru the trans neutral switch, if none into the switch, there is probably something awry in the vats starter relay. A trouble tree/ wiring diagram for the condition is required to go further here.

[pithi69]

Do you know if I can change the VATS starter relay? The anti-theft light does not come on. I changed the ignition switch and put in a new ignition today making sure the resistance to the VATS system is still the same and still nothing. Maybe I should trace the purple wire to wherever it goes and see if theres a broken wire somewhere...

[maxwedge]

See if you have 12v on cranking going in and out of the trans neutral switch first.

[ponchonutty]

Does the security light come on at all even when you first turn on the car during the bulb check? If not you may have a blown fuse or even a faulty light bulb and I've seen some of these GM cars not starting because of a bulb problem.

[pithi69]

Originally Posted by ponchonutty

Does the security light come on at all even when you first turn on the car during the bulb check? If not you may have a blown fuse or even a faulty light bulb and I've seen some of these GM cars not starting because of a bulb problem.

Wow Really?? I've checked the fuses, probably the first thing I checked, so I guess I need to see if I have a blown bulb!!

[pithi69]

The bulb was burnt out, now the Anti-Theft flashes constantly when the key is off. As soon as the key is turned it will stop flashing. I by-passed just the key following this website "http://vats.likeabigdog.com/" maybe I need to by-pass the whole VATS system? I found this website "http://www.drdetailshop.com/gmpellet.htm." Would doing this be a help??

Where is the trans neutral switch? If I shift into drive the locks will lock automatically so I guess the neutral switch is working?

[maxwedge]

It is on the trans linkage where it goes into the trans on top. Have you check for cranking voltage across the connector as suggested?

[pithi69]

Hey Maxwedge, I checked the voltage at the neutral saftey switch and I am only getting 12volts at the orange w/ black stripe and blue wire. No voltage is going to the thick yellow wire, green w/black stripe, black w/ white stripe and green wires.

[ponchonutty]

Not sure if you have the correct saftey switch. I thought they were only 2 wire systems???? Did you test it while in other gears to see if any of those wires changed state?

You shouldn't have to bypass the VATS system. What you state sounds like it's OK. It should always flash when vehicle is off, come on for a few seconds when you turn the key, then go back off while it starts. If it comes on solid then you have an issue.