Pontiac G8 Forum banner
1 - 20 of 22 Posts

·
Registered
Joined
·
715 Posts
Discussion Starter · #1 ·
On my way to work today, i was in traffic and i was driving and all of a sudden i noticed the car was stuck in 3rd gear in normal driving mode. So i went and put it in sport mode and nothing changed just stayed in "S3" tried manual mode and nothing would change. Luckily i was about a mile from work. I did get a CEL but i havent scanned for the code yet. I got to work and turned the car off and back on and now the trans seems to work fine again.

Also i will randomly get a stability trac on/off once in awhile while the car either idles for awhile or right when i talk off. Keep in mind with this cam i experience a lot of push and the shakes at idle so i dont know if that has anything to do with it.

Im more curious to see if anyone has ever had this problem. Im guessing its a module issue but i dont know.
 

·
Registered
Joined
·
201 Posts
Dealing with this now. Third gear is limp mode I guess. In My case,theTrans solenoids are stuck half way. I read there was a TSB about these. With them stuck you need to monitor your trans temps. Try not to let it get too hot. You will need to get the codes then go from there. Good luck

Sent from AutoGuide.com Free App
 

·
Capital City G8
Joined
·
3,219 Posts
This can happen if trans temps climb too high or can be a sign of big trouble.
 

·
Registered
Joined
·
1,210 Posts
Copy and paste from SI


If the transmission is in 1st, 2nd or 3rd gear during a transmission electrical component failure, the transmission will default to 3rd gear. All solenoids will default to their normal state. If the torque converter clutch was applied, it will release. This default action will enable the vehicle to be safely driven to a service centre.

1-2-3-4 CLUTCH STAYS APPLIED
Shift Solenoid 2

Shift solenoid 2 defaults to it's normally-closed state (OFF), and SOL 2 fluid exhausts through the solenoid.

Clutch Select Valve 3

Sol 2 fluid pressure no longer holds the clutch select valve 3 open. When the valve moves back to the closed position, it opens the 1234 clutch default fluid circuit, and 1234 default fluid is routed to the 1-2-3-4 clutch regulator valve.

1-2-3-4 Clutch Regulator Valve

With the absence of PCS 1234 clutch fluid, due to the default state of the C1234 pressure control solenoid 5, the 1-2-3-4 regulator valve closes from spring force. However, the 1234 clutch default fluid enters behind the 1-2-3-4 regulator shuttle valve and keeps the valve in the open position.

1-2-3-4 Clutch

With the 1-2-3-4 clutch regulator valve still held in the open position, the 1-2-3-4 clutch will stay applied.

3-5 REVERSE CLUTCH APPLIED or APPLIES
C35R Pressure Control Solenoid 2

The normal state for the C35R pressure control solenoid 2 is ON, therefore PSC 35 reverse clutch fluid will still be routed to the 3-5 reverse clutch regulator valve and the 3-5 reverse clutch boost valve.

3-5 Reverse Clutch Regulator Valve

PCS 3-5 reverse clutch fluid moves the 3-5 reverse clutch regulator valve against 3-5 reverse clutch regulator valve spring force and 3-5 reverse clutch feedback fluid. This allows 3-5 reverse feed to pass through the valve and enter the 3-5 reverse clutch circuit. 3-5 reverse clutch fluid is then routed to the 3-5 reverse clutch, the 3-5 reverse boost valve and the clutch select valve 2. When the 3-5 reverse clutch regulator valve is in this position, PS1 fluid from the pressure switch 1 exhausts through the valve, allowing the switch to close.

3-5 Reverse Clutch Boost Valve

PCS 3-5 reverse clutch fluid pressure acts on a differential area moving the 3-5 reverse clutch boost valve against the 3-5 reverse clutch boost valve spring. 3-5 reverse clutch fluid passes through the valve and enters the 3-5 reverse clutch feedback circuit. As PCS 3-5 reverse clutch fluid pressure is increased to a given value, the 3-5 reverse clutch boost valve opens the 3-5 reverse clutch feedback circuit to exhaust. This results in the 3-5 reverse clutch regulator valve moving to the full feed position sending full 3-5 reverse clutch feed pressure (full line pressure) to the clutch.

3-5 Reverse Clutch

3-5 reverse clutch fluid enters the 1-2-3-4 & 3-5 reverse clutch housing to move the piston against spring force combined with force from the compensator to apply the 3-5 reverse clutch plates.
 

·
Registered
Joined
·
715 Posts
Discussion Starter · #5 ·
Well here are the codes i pulled tonight. the CEL went away on the way home and trans worked fine.

 

·
Registered
Joined
·
1,610 Posts
On my way to work today, i was in traffic and i was driving and all of a sudden i noticed the car was stuck in 3rd gear in normal driving mode. So i went and put it in sport mode and nothing changed just stayed in "S3" tried manual mode and nothing would change. Luckily i was about a mile from work. I did get a CEL but i havent scanned for the code yet. I got to work and turned the car off and back on and now the trans seems to work fine again.

Also i will randomly get a stability trac on/off once in awhile while the car either idles for awhile or right when i talk off. Keep in mind with this cam i experience a lot of push and the shakes at idle so i dont know if that has anything to do with it.

Im more curious to see if anyone has ever had this problem. Im guessing its a module issue but i dont know.
Truly sorry to hear of your concerns. Please let me know if you'd need to make a dealership appointment. I'd be more than happy to do that for you. Feel free to message me anytime and reference your concerns if you choose to do so.

William R.
GM Customer Care
 

·
Premium Member
Joined
·
4,210 Posts
I can remember when I was misfiring like crazy after my header install (I cracked a plug or two). The car was lurching and stumbling bad and the Traction Control Off symbol kept flashing on and off in the display. P0300 is a multiple misfire code if I recall right.
 

·
Registered
Joined
·
715 Posts
Discussion Starter · #9 ·
I can remember when I was misfiring like crazy after my header install (I cracked a plug or two). The car was lurching and stumbling bad and the Traction Control Off symbol kept flashing on and off in the display. P0300 is a multiple misfire code if I recall right.
I got the idle set to low for the cam. I only develop a misfire once in awhile not all time.
 

·
HPT Pro Tuner
Joined
·
3,815 Posts
If P0300 is in the history is because the car was misfiring, the misfires can be induced by the cam, or they could be real, Also, Shane had the same P0716 back in 2009 http://www.hptuners.com/forum/showthread.php?27273-Weird&highlight=p0716, but nobody chimed in with an explanation, he didn't say if the car was misfiring or not in that thread. He checked the VSS sensor to see if something was amiss, but never posted if he found a solution or not, apparently his car was throwing p0716 once in a big while during hard acceleration. Hopefully the issue is going to be related to the misfires.
 

·
Registered
Joined
·
715 Posts
Discussion Starter · #11 ·
If P0300 is in the history is because the car was misfiring, the misfires can be induced by the cam, or they could be real, Also, Shane had the same P0716 back in 2009 http://www.hptuners.com/forum/showthread.php?27273-Weird&highlight=p0716, but nobody chimed in with an explanation, he didn't say if the car was misfiring or not in that thread. He checked the VSS sensor to see if something was amiss, but never posted if he found a solution or not, apparently his car was throwing p0716 once in a big while during hard acceleration. Hopefully the issue is going to be related to the misfires.
That very well could be because when I get my ESP to randomly get turned off is when the car is idling at stop lights which may be caused by the misfire like u said. It's misfired and through the code a hand full of times but nothing like it did today.
 

·
Registered
Joined
·
1,210 Posts
P0300 is such a crappy code. You can pull it out of just about anything. All it has to do is detect a couple misfires and it throws it. Can you pull up the misfire monitor screen to see which cylinder? I'd start looking at trans input/output data while driving and see if the number dont match. On a stock converter, ISS should be near engine RPM.
 

·
Registered
Joined
·
55 Posts
Well here are the codes i pulled tonight. the CEL went away on the way home and trans worked fine.

I'm having the same issue with my car. Did you ever figure out what the problem was?
 

·
Registered
Joined
·
1,261 Posts
Sounds like what I had.... Could be a wire issue or the trans is getting to hot. p0700 is generic and could be a lot of things. pretty sure I have had the p0716 also which IIRC was due to a wire issue at the trans connector.
 

·
Registered
Joined
·
263 Posts
I kind of got on mine a little bit and Wensday it popped the p0700 and p0716 codes. Ive had the p0700 before and its usually when my trans gets hot but goes away when the car sits for a while and cools down. But as of last night the check engine light hasnt gone off. It does seem to be driving fine but I only drove it around the block
 

·
Registered
Joined
·
263 Posts
can I unplug the battery to reset the codes and maybe it will fix the speed sensor issue or will that hurt the tune.
 

·
Registered
Joined
·
263 Posts
So I just now took the car driving around town trying to see if the 2 cel codes (p0700/p0716) would go out but it didn't and not really sure what the issue is or how to fix it and there's not much on the internet about it. Does anyone know what to do?
 
1 - 20 of 22 Posts
Top