Computer Reset?

EdsPony · #1 02-21-2005, 10:03 PM

I have a 98 GTP and I need to reset the computer.
I have unhooked the battery for hours and it doesn't seem to work.
Is there any trick to resetting the computer on these cars?
Either that or I have more problems than I think.

Thanks
Ed

Ripn12s · #2 02-21-2005, 10:08 PM

Unhooking the neg terminal on the battery for 1/2 hr should do the trick. What exactly are you hoping goes away?????

kustomkid54 · #3 02-21-2005, 10:13 PM

The fastest way I know to get it reset, is take it to the dealer for a tune up. Works everytime.

Quote:

Originally Posted by Ripn12s

Unhooking the neg terminal on the battery for 1/2 hr should do the trick. What exactly are you hoping goes away?????

BNaylor · #4 02-22-2005, 08:01 AM

Quote:

Originally Posted by EdsPony

I have a 98 GTP and I need to reset the computer.
I have unhooked the battery for hours and it doesn't seem to work.
Is there any trick to resetting the computer on these cars?
Either that or I have more problems than I think.

Thanks
Ed

Are you trying to clear a Service Engine Soon (SES) Light? If so, the best way is to disconnect the positive battery cable. Then turn your ignition key to the full on/start position and hold for at least 60 seconds.
Then turn the key to the off position. Now re-connect the battery positive cable. Now start the engine and the SES light should be off.

This procedure resets the SES light and clears all ECM/PCM DTC codes.
However, if you have a bonifide ECM/PCM problem, the error is likely to return after 1 to 3 drive cycles or sooner. You will need to reset your clock, etc afterwards.

Another option to to buy an ODB-II Code Reader which will have a reset button to clear DTCs and SES light. Comes in handy when you want to verify DTC codes, save money and do your own work on the car, especially if it is out of warranty.

Good luck!

2001 Buick Regal GS/1999 Regal LS

EdsPony · #5 02-22-2005, 08:11 AM

Actually I put a Short ram intake on it and I ruined the screen when I did. The car ran fine for about 4 days I think, this is my wife's car so she was driving, then it started hesitating and missfiring at WOT. I have since replaced the screen and it was still doing it wanted to reset the computer before I started to troubleshoot the ignition.

Thanks
Ed

kustomkid54 · #6 02-22-2005, 08:23 AM

You sure you didn't suck anything in when this happened?

Quote:

Originally Posted by EdsPony

Actually I put a Short ram intake on it and I ruined the screen when I did. The car ran fine for about 4 days I think, this is my wife's car so she was driving, then it started hesitating and missfiring at WOT. I have since replaced the screen and it was still doing it wanted to reset the computer before I started to troubleshoot the ignition.

Thanks
Ed

EdsPony · #7 02-22-2005, 08:29 AM

Don't think so throttle body is clean and the MAF is working fine.

kustomkid54 · #8 02-22-2005, 08:36 AM

If it's misfireing it has to bring up some numbers. Scan it and see what you come up with.

Quote:

Originally Posted by EdsPony

Actually I put a Short ram intake on it and I ruined the screen when I did. The car ran fine for about 4 days I think, this is my wife's car so she was driving, then it started hesitating and missfiring at WOT. I have since replaced the screen and it was still doing it wanted to reset the computer before I started to troubleshoot the ignition.

Thanks
Ed

EdsPony · #9 02-22-2005, 08:42 AM

Quote:

Originally Posted by kustomkid54

If it's misfireing it has to bring up some numbers. Scan it and see what you come up with.

It comes up with a random missfire code

kustomkid54 · #10 02-22-2005, 08:55 AM

Damn, I hate those. Could be just about anything. Plugs, wires, I had a wire go bad that runs over the top of the rad. Took five days and a lot of luck.
Check wires, and all the "dumb" stuff. If you can find it, I'll email you where the wire was that I found.
You would think they'd come with a computer that says "it's #1 plug wire".
Good luck.

Quote:

Originally Posted by EdsPony

It comes up with a random missfire code

BNaylor · #11 02-22-2005, 11:15 AM

Quote:

Originally Posted by EdsPony

Actually I put a Short ram intake on it and I ruined the screen when I did. The car ran fine for about 4 days I think, this is my wife's car so she was driving, then it started hesitating and missfiring at WOT. I have since replaced the screen and it was still doing it wanted to reset the computer before I started to troubleshoot the ignition.

Thanks
Ed

What brand short ram air intake did you install? If you do all the basics such as plugs, wires, fuel filter, check fuel injectors and still have the WOT miss you might want to look into your MAF sensor, especially if it is stock or has never been replaced. The stock MAF leaves a lot to be desired when you apply an intake modification to include CAI, etc. Are you sure your MAF sensor is OK?

During hard acceleration (WOT), the ECM/PCM operates in open loop mode and the MAF sensor input is critical. The new induction system allows alot more air to flow and you may get additional air turbulence, etc.

I had a similar problem with my son's '97 GTP when we installed a Thrasher CAI last year. It missed at WOT or any hard acceleration.
No SES light or DTC codes after a scan.

We cured the problem by replacing the stock MAF with a Granatelli Racing MAF sensor with cold air tuning capability. Hasn't missed a beat since.

2001 Buick Regal GS/1999 Buick Regal LS and ---->
1997 Pontiac GrandPrix GTP - Thrasher 3.4 SC pulley, Trasher CAI,
u bend delete, hi-flow CAT, Granatelli MAF, ASE Performance Chip.
ET:14.3 @ 96mph

wylie · #12 02-24-2005, 09:06 AM

Sorry if I'm a little OT here but I have to ask.
I have to replace a MAF sensor.
Would there be much difference between a stock MAF or a Granatelli Racing MAF sensor on a stock 99GT?
Also, ether or, do I have to reset the computer?

BNaylor · #13 02-24-2005, 10:27 AM

Quote:

Originally Posted by wylie

Sorry if I'm a little OT here but I have to ask.
I have to replace a MAF sensor.
Would there be much difference between a stock MAF or a Granatelli Racing MAF sensor on a stock 99GT?
Also, ether or, do I have to reset the computer?

From what I understand and know there is definitely a performance difference between the Granatelli MAF sensor assembly and a stock unit. Granatelli makes one for the GT (non-supercharged) and if a CAI modification is not of concern. You probably won't need the one with cold air tuning capability and will save on the cost. They are on EBay for around $269 plus shipping. The Granatelli MAFs have better calibration and supposedly inhibits the computer from learning the mod and cancelling out its effects after a drive cycle of up to 200 miles. There are gains of HP according to Granatelli equating to better acceleration and responsiveness. I lot of people swear by them via testimonials at their web site. Possible 10 -23 hp gain.

We needed one out of necessity because of the Thrasher CAI mod and the lean condition at WOT on our '97 GTP.

web site: www.granatellimotorsports.com

It is highly recommended to reset your ECM/PCM computer after this type of modification but not mandatory. Good luck!

wylie · #14 02-24-2005, 10:41 AM

Thanx bnaylor3400.

RugerP90DC · #15 03-04-2005, 10:39 PM

Quote:

Originally Posted by EdsPony

I have a 98 GTP and I need to reset the computer.
I have unhooked the battery for hours and it doesn't seem to work.
Is there any trick to resetting the computer on these cars?
Either that or I have more problems than I think.

Thanks
Ed

Just a litttle quick note on reseting your Grand Prix's computer without having to disconnect any wires or the battery. Turn the car to the "on" position, with out turning over the engine, then you tap the gas pedal 3 consecutive times you should see your display blink on and off 3 times and that's how you know you have for sure reset the cars computer! Turn your car "off" and then you can start your car and that's it!!!!!!

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