• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

GTP runs then dies 5 seconds later - help!

jwainGTP

jwainGTP

New member
Hey guys new member here, had to join because for the life of my I can't figure this out! Seems to be a security issue, but read everything becasue it's damn bazaar.
So my car wouldn't start a week ago and I thought originally it was something mechanical so i threw on a scanner and no codes came up. So i changed my coil packs, coils & plugs. No fix, so I test spark on each coil just to be sure, and they're good. Fuel pressure read at 50psi so i knew i had fuel. Buddy told me about the security issues these have so I changed the tumber/lock cylinder and programed the new key and she started right up. Awesome right?
Well here we are 3 days later getting reading to leave work and she cranks and tunrs over like normal and then 5 seconds later dies- started it again, 5 seconds later it dies. Does it every time. So i try the 10 minute thing (twice) and nothing.. I think its related to the security system but it has the new tumbler and worked fine for 3 days. What else is left? Shouldn't the 10 minite thing work?! And guidence or ideas on my next step would be greatly appreciated!

Going to unplug the battery and touch the terminals together tod completly drain all the power from the system then try again - doubtful that'll do anything though.

Sent from my SPH-L710 using Tapatalk
 


If your car is a 1997-2000 GTP.

Do this and it will likely start, your problem sounds pretty much like this.
FuelResistorGP.jpg
 
Fivefingerdeathpunch said:
If your car is a 1997-2000 GTP.

Do this and it will likely start, your problem sounds pretty much like this.
FuelResistorGP.jpg
Click to expand...
Its a 2001, so is that no longer relevant?

I called a gm dealer and got transfered around until they put their "master mechanic" on the phone and he said the passkey III (which is my security system) if the key programming process isn't done perfectly it will go into a mode which allows the ignition cylinder to communicate with the bcm to let the key work 50 times - so 25 starts and 25 times i can turn the car off before it trips the security system and kills the fuel once started. He said I can unhook the battery and drain all the power from the car by letting it sit and rehooking it giving me another 50 turns. How insane!!
Anyways he said when i get home reprogram the key and i should be go, if not ill know in 50 key turns... ridiclous... thanka GM.

Sent from my SPH-L710 using Tapatalk
 
That sounds like BS to me. You either did it right or wrong. It either works or doesn't. Did you get a secruity light in the dash or DIC?

Jeff
 
Well i unhooked the battery like he said and let it sit for a while to drain the power and when i hooked it back up it fired up... at this point i believe him. Was able to get the car home and reprogrammed the key. Everything seems okay right now, but im still unsure of how long it will continue starting...

Security was coming on with doors open and no key in the ignition. Once i put the key in, the light goes away.

Sent from my SPH-L710 using Tapatalk
 


I've had this happen on two different GTP's. Both turned out to be the Mass Air Flow (MAF) sensor. There is a way to check for this, even if your car doesn't throw a code (mine did not either time). Remove the engine cover. Have someone start the engine. With two fingers, tap as hard on the MAF sensor like you would as if you would knock on a door. If the engine stumbles or dies, it's your MAF. This is a test that a certified Mr Goodwrench mechanic taught me. Second, if your engine just keeps dying, turn off the ignition, open the hood, remove the engine cover and unplug the MAF sensor. Then start the engine. If it now runs, you know it's the MAF sensor. You can drive it this way for a while as the ECM will use default values. This will cause the check engine light to come on, but this method will get you home. Get a new or rebuilt MAF. You will need a Torx bit made for the bolts with the center security pin. You can get these at most parts stores. Install the new MAF sensor (very easy) and have the check engine code cleared.
 
Security light goes away once started.. Im going to try you're maf trick, just in case

Sent from my SPH-L710 using Tapatalk
 
So here we are a couple days later and its back to doing the same thing!!! Im 100% sure the key is programmed perfectly.
So after unhooking the battery and letting the system drain, the car will run for was seems to be a consistent 3 days, or what the mechanic said; 50 key turns. Not sure if thats relevant as the key is definitely programmed correctly. Idk what could be causing this...

Sent from my SPH-L710 using Tapatalk
 
Not sure.. ive already reset the system so it wont do it for another 2-3 days. Im assuming it would be fuel being cut

Sent from my SPH-L710 using Tapatalk
 


Has to be security system related, mechanically the car is sound.

It has an aftermarket remote start which means it has to have an aftermarket security system too, right?

Sent from my SPH-L710 using Tapatalk
 
More than likely, if it is an aftermarket remote start then it already is an aftermarket alarm too. There are stand alone units as well but they usually have antitheft device built in as well. Try bypassing the aftermarket part and see if that clears it up. Another thing is that back when I did a lot of remote starts we would use a customers key. This key would have a piece of wire wrapped around the key then take one end and run it to a relay. The other end would go up to the ignition switch then back to the relay. When the remote start was active it would close the relay and complete the loop so that the PCM would "see" the key. A lot of lazy installers would not add the relay and end up coming back with issues kind of like you are describing. You may be confusing the system if it sees 2 keys at the same time when you are doing a relearn, but someone else may want to chime in on this I've been out of the business for a while. When I started getting out there were data bus modules that would communicate to the car and basically tell the car the key was present and you didn't have to use a key, but did have to program more than one key to the unit. Now I have been to the JY several times and found cars with remote starts in them and I am still finding keys wrapped up in electrical tape on the harness, so you might want to get in there and find out what you have and how it is installed.

Jeff
 
Ok, ill take a look! To bypass it, would just unhooking it do the trick?
I am not one for electrical

Sent from my SPH-L710 using Tapatalk
 
Alarm wiring is pretty standard. You should have 2 fuses on some larger gauge wires, should be red you will probably notice other fuses usually parking lights and any powered relays external should be fused. Look for wiring just under the dash and keep an eye out for a key just in there, it may be wrapped in electrical tape. A razor blade will be your friend for carefully cutting away tape. To remove the key just be careful with it so you can put everything back together. Hopefully your young but when I did work I would put my feet up on the headrest and get up under the dash to see what's going on. Get a flashlight too.

Jeff
 
Yep, young and agile lol.

So just removal of the key under the dash will solve the problem??

Sent from my SPH-L710 using Tapatalk
 


That I do not know, I am thinking that it may interfere with the process if the car sees 2 keys at a time though. Don't forget to check for fuel and spark when it goes dead on you again though as asked previously. Check for spark by removing one plug wire (twist it until its loose, if it happens to be stuck and doesn't come off easily) insert a screwdriver and hold it away from something metal about 3/8" away and have someone crank it you should see sparks. Check for some fuel by listening for the clicking of the injectors and you can also turn on the key and just press the schrader valve and fuel should come out. Use common sense on that one, eye protection and such.

Jeff
 
Take a look at what is under the dash and record any names/model number etc. From there maybe we can tell you how that would have been hooked in and the best way to disable it.

For example, I'd usually suggest noting that the ignition or starter lead often gets routed through a relay.

Here is a link with a standard single throw relay. http://www.the12volt.com/relays/relays.asp If you had one of these, likely 87a is either empty or missing the pin. To bypass the alarm interrupting the circuit..you'd move the wire from 87 to 87A and disconnect 86 and or 85. That way the signal goes straight through the relay w/o being interrupted.
 
The car always starts and then dies after a few seconds. It doesn't crank and not start. So how could i tell if the fuel or spark is being cut? Obviously one of the two are
Ill check on the brand of the remote start and security system after work

Sent from my SPH-L710 using Tapatalk
 
You must log in or register to reply here.
Back
Top