Last post on Jul 28, 2011 at 9:56 PM
You are in the Pontiac Grand Prix
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Pontiac Grand Prix, Sedan
#4405 of 4457 Re: 1990 Pontiac Grand Prix Rough idle [headach]
Aug 01, 2008 (5:53 pm)
Hi, I also have a 1990 pontiac grand prix. I think your problem is with the idle learn control. Any time the battery is disconnected for a period of time the computer(ecm) loses its idle learn memory and defaults to preset value. It will now have to be re programmed with the correct values. This can be done at your GM dealer for the cost of around $80.00 , depending where you are located. This is unique to 1998 through probably 1991 or 1992 pontiac models. After 92 GM fixed the problem and all you had to do was drive the car for about 10 miles at a proper speed above fifty mph. This would over write the limp back codes set in the ecm after losing the battery voltage for a period of time.
I just replaced the radio in my pontiac and had the battery disconnected for two days, i now have to have the ecm re programmed with the correct values for the idle learn control. Symptoms are rough idle, stalling, engine surge and some times rough shifting when the torque convertor locks up putting the car in direct drive.
Hope this was helpful
Post if this fixes your problem
#4406 of 4457 Replacing instrumentation bulbs
Aug 23, 2008 (3:25 am)
My 2004 Grand Prix GT has a few bulbs burrt out on the instrumentation panel. 4 on the radio buttons as well as the re-circulation button on the climate control.
Can these bulbs be replaced without changing the entire console?
#4407 of 4457 Re: Welcome... [L8_Apex]
Aug 26, 2008 (10:46 am)
Wider is better!! more ground coverage makes it easier to corner. of course better tires and suspension will help too!
#4408 of 4457 Re: Welcome... [L8_Apex]
Aug 26, 2008 (10:52 am)
I have a very strange problem that has never happened to me before. everyone always gets a kick outta this.
I was driving to work one morning back in early july and went to turn on my a/c to keep me a little cool on the highway. As SOON as i turned it on the fan come on and stayed on. Even if i turned the knob for the speed control to off it would still stay on as well as when i turned the car off and took the key out it stayed on as well. Now i'm not a mechanic by any means, but i do understand the basics of how cars work. I'm pretty sure its an electrical problem but not sure where to look. Its not the switches (for the speed, temp, and vent selection) because once you disconnect them it still stays on. I've checked ALL the fuses and relays and they're all good still. The only way to get the fan to turn off is to disconnect it behind the dashboard where the climate control switch is also plugged in. But because of this i cannot use the a/c, heat, and rear defroster. Not having a/c is ok, but when it starts to get colder out, especially in jersey, its not going to be fun with no heat.
please let me know of any suggestions on the problem as i'm sure a mechanic would have field day with this! thank you!
#4409 of 4457 Re: Replacing instrumentation bulbs [nkairns]
Aug 28, 2008 (5:26 am)
My stereo has a couple bulbs burnt out as well, none on the dashboard, but not sure if i can just replace the bulbs as well either....
#4410 of 4457 Replacing Instrumentation bulbs
Aug 29, 2008 (10:35 am)
It appears the dealer has to remove the radio and send it out to some after market place to have the bulbs replaced. Too much of a hassle for me and probably tremdously expensive as well. I'll simply live with a couple of missing radio button lights.
#4411 of 4457 Changing rear spark plugs on 04 GP
Sep 21, 2008 (10:08 am)
I have an 04 GP with 40k miles. I've had this car for over a year. The car is idling rough. This started yesterday. I replaced the front three plugs however I'm having problems pulling the rear three out. Not enough room for leverage to pull the spark plug boots. Any suggestions?
#4412 of 4457 2004 GP HUD
Sep 22, 2008 (7:00 pm)
The HUD on my 2004 GP stopped functioning, There is no sign of any operation. Does anyone know where the fuse or fuses are for this? I didn't see a labeled power source at the fuse panel on the passengers side, Is there another location?
#4413 of 4457 Re: 2004 GP HUD [gpguy]
Nov 12, 2008 (9:59 am)
had same problem. On passenger side kick plate there is a fuse panel and there is a fuse box. for me it was not the case. Took it to te dealer $860 dollars for new and install. '04 45K mles w/o warranty.
#4414 of 4457 2004 humming/buzzing
Dec 03, 2008 (3:56 pm)
I have a 2004 GT2, 28,000 miles. There is a constant humming/buzzing that is just barely audible when pressing the accelorator. The pitch of the noise changes with the RPMs of the engine. I'm not concerned about the noise itself, as my Hyundai Sonata does the same thing. My concern is that occasionally, mainly after hard accelerations, this noise gets so loud it almost drowns out all other noises in the car. It will last for several minutes, one time lasting a few days. It gets progressively quiter until it is back to normal level after the car has been driven a while. Does anyone have any insight on this? It is very intermittent, so I don't want to mess with a dealer just yet.