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P1811 code 2005 Grand Prix 91,000 miles

hampshire32000

New member
I have a 2005 Pontiac Grand Prix GT. The car shifts hard from 1st to 2nd and 2nd to 3rd once in a great while. If I stop and shut the car off and start it again it goes away. The car did produce a code of P1811. The vehicle has 91,000 miles on it and I have not changed the trans fluid yet. I have been told it is one of three problems.

The silonoid needs to be replaced: about $500

The trans need to be rebuilt: about $1400

The ingition is going bad: not sure on the amount


I just want to fix this once, with the info I gave above can anyone point me in the right direction.


Thanks,
Jeremy
 


Well, I’m no tranny expert but your shifting problem could be the 1-2 solenoid. But most likely you have a burnt clutch. If that is the case a rebuild is in order. Or you could have the line pressure bumped up and the fluid changed, that might mask the problem for a while.:th_mischievious:

Ignitions on GPs are nearly bullet proof, so yours going bad sounds like a hick mechanic con.:th_angry-teeth: Are you misfiring? Also, be aware that it is time for new plugs and wires if they have never been changed.
 
1811 is max adapt long shift... bad pressure control solenoid... 500 is too much to get it fixed... i got mine done at a reputable shop for 250.
 
^ That it is. I got my car scanned today and that is what is wrong with mine. I was quoted $350 for mine including replacing some valve body parts too.
 


ok so i got an 04 gp gt with 174,000. 85% highway. shifts had from 1-2 and 2-3. if i clear the code it goes away for awhile then comes back. i no that its usually the solenoid but since my car is such high miles could the clutches be worn enough to be causing the .65 sec long shift. it did it before a 2400 mile road trip last summer and didnt do it again till december. did it yesterday then again to day. im kinda hoping the trans doesnt need replaced then again kinda want it replaced(then i get to give Dave a call.) im goin to try the trans kit and external trans cooler and see what that does
 
how intrusive is replacing the solenoid. if thats what it needs i wouldnt mind doing it, being its not too intrusive.
 
u need to get it scanned for codes, if it is indeed the Pressure control solenoid which i would put money on... its accessible through side pan on transmission. can be a b*tch without a lift but it is possible.
 


99.99999% of the time the pressure control solenoid causes that code.... its a known fact. ive had to replace 2 for same probs u are experiencing... get the updated solenoid from dave @ triple edge performance. they only like 50 bucks.
 
I am New We are having the same issue with our 2005 GT. So far the dealership flushed the tranny and now reset the computer and put new firmware on the computer. Will this new firm ware fix the code p1811? Or will it still hard shift? Thanks
 
The side cover itself is easy as cake. Getting there is another story. Use a deep socket on all but the bottom 4 bolts. The bottom 4 bolts are a Torx T40 that likes to get rounded off on you.... Once all those bolts are off, It should look something like this.
DSC01802.jpg


Now you see the solenoids, on the far left. The pressure control solenoid is the middle one with the grey clip. There's a retaining clip holding it in place. Use a pair of snap ring pliers to pull the clip out. The solenoid should come out.

Installation is reverse of install.
 
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