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Pontiac Grand Prix Starting / Stalling Issues



  • Check signals from Ignition Control module to the Powertrain Control Module ( there are four signals two for Crank Position Sensor and 2 for Cam Shaft Position Sensor) Pin to pin tests are need to resolve this issue not a scan diagnostic tool. If you have the four signals going into the Powertrain Control Module (PCM) also reffered to as the Engine Control Module (ECM) the checking of the signals should be done when the car is in the state of cutting off when warm and not starting. If the four signals are not coming out of the Ignition Control Module (ICM) then check the two signals from the Crank Position Sensor (CPS) and Camshaft Position Sensor (CAMPS) going into the Ignition Control Module (ICM). The two sensors are located behind the crank shaft pulley Harmonic Balancer. If one of the signals are not coming into the ICM then you will not have a spark. If everything checks out as above then you would need to check the ignition control signal from the Powertrain Control Module (PCM) back to the Ignition Control Module (ICM) this is the signal that tells the coils to fire on top of the Ignition Control Module (ICM).

    I had the same issue with my 2007 Grand Prix and did all the pin to pin test to find out what the problem and root cause for me was the Crank Position Sensor (CPS) no signal from the CPS at all.

    I first took the advice from what was done by other posters from other websites and changed the ICM with a aftermarket ICM (DURALAST) and that caused more issues because it would contantly over heat and cause the car to cutoff. The duralast ICM for these cars are not up to OEM Specs even though they say it is OEM Specs.

    I replaced the CPS after the first Duralast ICM and put another duralast ICM on the car and car would cutoff and the duralast ICM would be super hot. Then I put back my origin GM ICM back in the car and have not had a problem with the car getting and cutting off.

    You would not get any codes for a CPS or ICM being bad all other parts ie. MAF, MAP, IAF, EGR, Fuel Pump, Injectors, and O2 sensors will throw out codes. The Crank Position Sensor and Camshaft Position Sensor are the weak points in this Ignitions systems because of the nature and where they located in the engine block heat will cause these parts to fail in time and will cause car to cutoff when hot and not start again until cooled off. Fuel pumps will plain quit working and never start working again. You need fire and gas for a car to start. No gas pressure at fuel rail no start, No fire from Coils no start.
  • My 06 Grand Prix doesnt wanna start in the cold this year. I have checked the battery while it is running, and the battery is right around 14 volts. I have had an issue with one of the modules that controlled the headlights burning out, and having to be replaced. On the first attempt, I am not hearing anything out of the starter, but on the second try it clicks and starts up on me. When the car starts though, the date and time have all been reset. Any ideas on what this issue might be?
  • gmcustsvcgmcustsvc Posts: 4,251

    Let us know if you were going to get this checked into at the dealership. We certainly understand if you were looking into different options as you're outside of warranties at this point, but just wanted to offer to follow up on any dealer visits you may make.

    All the best,
    GM Customer Service
  • Hi all,

    Ok, I have been working on this for a few weeks with no solution. I have a 2002 Pontiac Grand Prix GT that is having starting issues that are getting worse. It takes several attempts and needs me to give her a lot of gas to get her to start. Once started, if she doesn't stall in the first 5-10 seconds, I am good to go...runs like a champ. Battery is new, starter new, alternator new, new intake gaskets (upper and lower), new upper manifold, new coolant tubes, and new valve cover gaskets. The problem started before all these new items were put in. I am guessing it is a sensor (MAP/MIP) or another one but they are way to expensive to "guess". A fuel issue? Any help you could give would be much appreciated.
  • Hi cosully777,
    Looks like you have done extensive work done but you don't mention anything about the spark plugs. That is usually a good place to start because it is cheap and easy and the sparks will tell if you have any issues with any cylinder or with the spark plug wires.

    Your problem sounds like an old carburator choke problem, you sure they didn't slip in a carburator when all the work was done :-) Mass Air flow can be another suspect but it gives a code, are you getting any codes. Mass Airflow costs $130 - 180 non GM, (I got 2 re-manufactured ones, they both failed ended up getting a new one for a $30 more), it is a 5 minute job to replace it.
  • Thanks for replying so quickly. No, I have a code reader and it is not throwing any codes The "check engine" light came on once last week for about 10min and went codes. I was debating about the spark plugs but I didn't know that if the spark plugs are bad the car can still start.

    So let's say it is a "carburator choke problem" what am I looking at to solve the issue? If you can't tell I am an amatuer home mechanic. I enjoy working on the car but this pontiac is one thing after another. Thanks for all the help!
  • did you get this resolved? I have a 2004 grand prix gt2 that is doing the exact same thing! Never know if I go to get in my car if it will give me problems starting. Sometimes it starts right up, other times I have to give it a few trys. I dont want to spend money guessing what it is and put money into the car that isnt needed. Help please!?!
  • NO, NOT YET!! It is getting very annoying. I checked the output on the battery and alternator again today and they are fine. It is below zero with the windchill here but it just started without a problem...that only happens once in a great while. I have no clue what to do...I think I am going to replace the spark plugs and O2 sensors and see what, if anything, that does. Let me know if you figure anything out.
  • damionsrdamionsr Posts: 2
    edited February 2013
    I have a 2003 Grand Prix GTP supercharged with 95xxx. The car was running great and all of a sudden I'm sitting at a light and the car shuts off and sets a check engine light. I go to restart and it and it wont restart without giving it some gas. Once it started it the idle fluctuated between 200 and 1000 rpm's. It set code P102. I noticed while the car running at idle i unplugged the IAT and the car ran better. When I plugged it back up it started running weird again. I replaced this sensor and drove the car around about an hour, ran beautiful. All of a sudden, I'm at a light and it cuts off again. Now I have to drive with two feet to keep it running because when I stop it just dies out. IT hasnt set any different codes, same code P102. When it acts like this it wont start unless i give it gas. If i just turn the ignition without giving it gas it doesnt start. After a few times of this it just turns over. If I let it sit for 2 minutes it starts up and runs fine, and then it will just shut down. Am I dealing with a MAF sensor issue or something else. I also didnt notice any vacuums hoses. Any help would be greatly appreciated.
  • The first thing I would look at is the Mass Air Flow sensor. I replaced mine twice, you should be able to look up the code. P102 points to MAF. Make sure you get a good one, doesn't have to be GM but watch out for the remanufactured ones. First I got a remanufactured MAF within 2 weeks it started acting up, then I took it back and got a new one and it was fine after that. It takes 5 minutes to replace it, it is on top of the engine.

    Good luck.
  • 99gtp99gtp Posts: 3
    99 GTP cranks but will not start, next day starts. drove for 2 days. Again will not start, had been setting for 2 hrs so not hot. Started next day fine. Next day dies at 50 mph (daughter describes like running out of gas still idle but 0 rpm) restarts go a little farther same thing again, takes back to campus, ran fine. 2 days later drives 110 miles home, fine. 2 days later I drive 10 miles to work, started and ran fine. 2 hrs later crank, no start. Could hear fuel pump running. Left key on popped hood checked connections, then car starts. Did fine rest of week, ran to warning on fuel level, filled to 3/4 tank, changed fuel filter let run for 15 min. 2-3 hrs later crank but no start. checked at bleeder on inj. tube had fuel. got back in car, started fine. Next day fine. 110 miles back to school. Monday starts and runs fine for 20 miles set for 4 hrs starts fine then stalls at 50mph a few miles up road, daughter tries to start several time, crank no start, told her to leave key on a couple min. starts and runs fine. Next day 110 miles back home fine. Help, I'm going nuts!
  • damionsrdamionsr Posts: 2
    Ok, now I'm frustrated. Took the car to a reputable GM dealer and they told me the MAF sensor plug was bad. Couldn't tell if the MAF was bad until we replaced the plug. Replaced the MAF sensor and plug, IAC. Take the car from the dealership, drive it and within the hour it's stalling again. only code it ever sets is 101. What it does is it can be running just fine, i come of the accelerator and the rpms drop to 500 and it's like the car is surging, the rpms are fluctuating as the car is fighting to keep running, give it a little gas and its fine. other times when you come off the gas the car dies instantly and it wont fire up unless you are giving it a little gas. the dealership cant seem to figure it out, fuel put is putting out a consistent 42 psi. another thing i notice is the boost for the supercharger is increasing when it should be. sometimes sitting at idle it flashes a couple of notches. i'm totally lost on this car!!
  • gmcustsvcgmcustsvc Posts: 4,251
    If you want for us to follow up on anything with your dealership, please contact us at with more details (including your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).
    Sarah, GM Customer Service
  • 99gtp99gtp Posts: 3
    OK car finally stalls and will not refire. Dealer mechanic diagnosis is crank sensor. $350 (with tow bill) running fine.
    Thought I would post result since I didn't get a reply or help on the first post.
  • john306john306 Posts: 2
    Assuming you have the 3.8 in the GT, cam and crank sensors have always been an issue. Holding the gas pedal down causes a clear flood signal to the ecm shutting down injectors though.
  • magus732magus732 Posts: 1
    Yeah, I've got a question. My 2001 Grand Prix GT has been "fixed" twice by a previous owner, and it stills stalls out randomly. Now normally, I'd just assume the problem was unrelated to whatever the mechanics fixed (i.e. MAF, cam and crank position sensors, which the previous owner told me were replaced before I got this car). But not long ago, my father was with me when it stalled out and he (who was an auto mechanic for 30-some years) suggested it's actually the security system randomly engaging, which makes some sense when you think about it. The 1997-2003 Grand Prix with an alarm system ( I don't know if they ALL have an alarm system or not...) have a Passkey III immobilizer-type setup that cuts power to the fuel pump and starter. This is EXACTLY what happens when it stalls out; the car will just suddenly die, with no warning at all except a shudder, and the "low oil pressure" and "low voltage" warning lights on the dash come on. When you try to restart, the fuel pump doesn't consistently engage, as if it's still trying to immobilize the car. Eventually it does restart, but it sometimes takes awhile. (This aspect, how many tries it takes to successfully restart, is also completely random).
    My question is this: since it's possible to deactivate the "content theft deterrent system" (which is, according to the owner's manual, the thing that actually cuts off power to the fuel pump and starter) without taking the car to a dealership, would this solve the problem?
  • Magnus, looks like you opened up a new frontier, thanks to your Dad. This is something I had not heard before. I had the stalling issue, but usually it started right away after a lot of research, the dealer replaced the crankshaft positioning sensor and it didn't have the problem again until I sold it.
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  • wardy269wardy269 Posts: 1
    Hi there,
    I have a 2001 grand prix that has 170000kms on it, always serviced and in good shape. It will stall randomly, whether I am stopped or going 50km. Some times it starts perfectly and others it has to be cranked over a couple times and then will shake like crazy, blow blue smoke out the mufflers, RPMs with rise and fall and then it quits. The oil and battery light comes on and thats it. After it stalls sometimes it starts right away, others can take 5-10 minutes. It has been to the GM dealer and hooked up to the computer, where they found nothing. The dealer is trying to tell me it is possible I blew a head gasket and coolant is now running into the motor and causing the smoke and for it to stall when the motor isnt hot enough to fire. Normally when your car is burning coolant it blows white smoke though. Said I need a new motor or to rebuild it. I feel like Im getting shafted, and will not fix it, as my car is not worth enough to spend the couple grand. I also see several related problems with CPS and ignition control modules and such. Has anyone has the same problem with the stalling and blue smoke
  • Ive got a 2006 grand prix with a 3.8. We just put a new transmission in it a week ago and it has just started the stalling thing, usually first thing in the morning it will shudder with the idle going up and down and then it will smoke and stall. my "Anti theft not programmed" message is showing up. also my remote for auto start and auto door locks have quit working, i have scanned the codes and all that comes up is PO108, it is really driving me crazy, please post if you find out what yours was.
  • I have a 2004 gtp Grand Prix that all the warranty lights come on in it when it gets wet I seen other post about this problem as being a speed sensor I just bought the car a month ago I have aul coverage on the car I guess I'm just wondering if anyone knows what the problem is bc I'm not to sure aul will cover a sensor going out?
  • nickosweetnickosweet Posts: 1
    edited July 2013
    I'm not sure if anyone can help me. I have a 2002 Grand Prix SE 3.1. It stalls out randomly while driving at low speeds or when stopped, it doesn't do it all the time but very frequent when it is. I had the alternator checked and replaced thebattery, cam shaft sensor, crank shaft sensor. I also completely cleaned up the ground to the car and what it was aattached to with no change. I can't seem to find a dealer or repair shop that can figure out the problem. It also at between 3000 and 4000 rpm will choke reallly bad and not gain any acceleration.

    I'm not sure if this is 100% but for the past week I have had it under half tank of gas and no issues what so ever you could step on the gas and no choking nothing but then I filled it last night and it started choking and stalling again. When it was doing it originally I had 3/4 of a tank. I just bought this car 2 weeks ago. When i drove it home had about 1/4 tank of gas and no issue at all. So I'm not sure if im just nuts in thinking gas has anything to do with it or not. Any advice tips or any information would be greatly appreciated! !!
  • Sounds like you have replaced quite a few parts but I didn't see you mention the Mass Air Flow sensor. Have you had it checked or replaced? It is not a cheap part but on my 3.8 liter engine it is a 5 minute job, you can do yourself.
    You don't have to get an original GM part but stay away from re-manufactured parts, I had to get a new non GM part. It solved the problems I was having which were very similar.
    Good luck!
  • In my 2001 Grand Prix I had a spare key made and hid it in a magnetic box under my car. I misplaced the original key and tried to use the spare one and after the car started it would die after a couple seconds. In the end I realized that nothing was wrong with my car and it was the key. Original keys have a chip inside them and when I tried to use the spare the security system would kill the car because it didn't have the chip in it. I was so relieved to find this out because I thought something was wrong with my car. I wanted to tell you thanks because it was this post you made that tipped me off to the possibility of a security issue vs. engine trouble. I found my original keys so I'm all good to go now. Thanks again! :)
  • On my 2005 Gran Prix the car will start fine and drive well when it is cold. If I go to the supermarket and let the car alone for fifteen minutes it doesn't want to start right away and then the tach swings around wildly. I put the car in gear and it lurches with almost no power. The mechanic fiddled with it last week cleaning the throttle body but it is doing the same thing. I just replaced the o2 sensor upstream as well as the mass air flow to know avail. Can anyone help?
  • its the idle control solenoid just went thru the same thing even if it has been replaced it could have been adjusted wrong if your still dealing with this prob let me know and i can go a little more in depth with whats going on hope this helps
  • nose2nose2 Posts: 1
    After a normal 20 minute drive, 99 grand prix died. On side of road, couldn't get it to start for several minutes (like it was out of gas, but had 1/3 tank). FInally did start , and made it last few miles to my destination. About 1 hr later, Went to leave, car started fine, backed out of parking spot, gave it some gas and it died again. Couldn't get it to start again. Eventually, if I pushed gas a fair amount during start, I could keep it turning at about 3000 rpm. But if I reduced gas, got very rough and would die. Went to buy some heet (First real cold day of winter). Came back (about 1/2 later) poured heet in, car started fine (I was sceptical that heet would work this fast). Let it idle, untouched, for about 5 minutes. Got back in, revvd engine, it purred nicely. Left for home, went a block or so, got on main street, gave it a little gas, and it died again. Tried to start it again, couldn't do it.
  • I hope you get a reply, mine does the same thing. Changed the computer and the crank sensor, no help.
  • twisted_onetwisted_one Posts: 2
    edited December 2013
    I have a 2001 pontiac grand prix, this thing has been nothing but an expense for the last 3 years. About 4 months ago the fuel pump and fuel filter was replaced, the car has been running great ever since till about a week ago I drove the car , after the running temperature was reached when accelerating the car engine (hesitated skips spits sputters bucks) not sure what exactly to call it, sounded like it shut down for a second or two then would kick back in when I would release the gas peddal and when its in park I also noticed the rpm guage fluctuates, but I notice it also fluctuated when set on cruise control... the service engine light did not come on right away... codes were read when it did kick on... got 2 codes P0171 - system too lean (bank 1) and P0443 - Evaporative emission control system Purge solenoid control circuit malfunction... had the purge solenoid replaced...still the code shows up... had the Ignition Control Module tested at Autozone all 3 coil packs ...thats good, the plugs and wires are about 8 months old, but they were removed and checked all good, gap is right on...Air filter is still fairly new and clean, Added a can of seafoam to clean fuel system and remove any water that might have been in the tank. Mind you the car starts right up first time...just rpm's fluctuates and when the running temperature is reached is when the other issue starts with the hesitaiton etc... This vehicle needs to desperately be fixed and service engine light off so it will pass the state inspection, I can't afford to take it to a shop, being I am on a fixed Income and raise my grandson and need this car to get him to and from school, doctors appointments etc... Any help would be greatly appreicated... Thanks in advance
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