2000 venture shifting trouble

[geovair66]

Hey there all,
ive got a 2000 venture that just last week started shifting hard in all gears, now thats seems to be ok as the van shift fine but i noticed yesterday its not shifting into overdrive. ill move the shift lever between 3rd and drive and nothing changes and there is a faint whine when drive is selected but not in 3rd. the engine runs and sound fine but the temp guage is erratic all of a sudden. the tranny fluid could stand to be changed but doesnt smell burnt. any ideas would be a great help and thanks in advance!!

[blazes9395]

The whine and hard shifting is a result of max line pressure commanded to the transmission by the PCM. You have to get it scanned and see what codes are coming up. Driving it with a hard shift and whine will destroy the transmission rather quickly, if damage has not been done already.

[geovair66]

the pcm was reset and the trans seems to be shifting and the whine is gone. when it is shifting to OD it seems as though it keeps switching back and forth from 3rd to OD on a slight grade( didnt do this in the past). i changed filter and fluid this am as it was due some time ago. the fluid was clean not burnt. it shifts fine in all other gears. any other ideas?

[Wr_guy]

Originally Posted by geovair66

the pcm was reset and the trans seems to be shifting and the whine is gone. when it is shifting to OD it seems as though it keeps switching back and forth from 3rd to OD on a slight grade( didnt do this in the past). i changed filter and fluid this am as it was due some time ago. the fluid was clean not burnt. it shifts fine in all other gears. any other ideas?

I have the same problem...it happens then goes away.

Where can I get the PCM cleared?

I recently changed the fluid and it ran fine for 4k miles

Fluid level is good.

Thanks

[geovair66]

Not sure you might try autozone! or advance, i think theyll clear an ecu fault but not sure about the pcm. a buddy of mine does my van for me! good luck!

[blazes9395]

This hard shifting/no-lock-up is usually commonly caused by a couple of things, or either of the two things. Usually if you restart the vehicle, the problem will go away for awhile and then come back. Sometimes it will only do it when the vehicle gets warm. If it is doing it when it gets warm, its usually an indication that the TCC Apply valve is worn.
What is happening is the the PCM(Powertrain Control Module) is commanding the TCC(Torque Convertor Clutch) to begin to engage, lock-up. As this is happening the PCM is monitoring the slip of the clutch. If the the TCC apply valve is not stroking as required, usually becasue its worn out, the PCM is noticing to much slip. At this point, the PCM will go into limp mode, the transmission will shift up too only third, and there will be hard shifts. its designed like this to reduce damage to the transmission. Sonnax industries makes a correction kit to fix this, and my opinion is the best fix if this is your problem. With this, the valve body must come out of the car and be fixed on the bench.

The other cause to this hard shifting problem can be caused by a bad or faulty EPC(Electronic Pressure Control) Solonoid. If it is found that this is the problem, then all that needs to be done is the EPC solonoid replaced and you should be good to go. This solonoid is found on the side cover, on the valve body.

With either cause to to be found, you have to have an transmission capable scanner and you have to have someone willing to honestly tell you what the problem is(assuming they can diagnose it properly too). Many tranny shops are relunctant to just replace the valve or solonoid becasue if the transmission was driven like this for long and was damaged, soon after it will be back to the shop. At this point, the customer is usually convinced that you damaged or didn't fix their transmission properly, and it becomes a nightmare for the customer and the shop for that matter.

[Wr_guy]

Thanks Blazes.

Mine has done it twice when it was stone cold and it was normal after a restart. It seems most folks get this shortly after changing the trans fliud. I'm guessing the PC solenoid is hanging up from time to time..possibly due to dirt stired up in the fulid change. BTW I've changed the fluid twice, once at 55 and again at 103k...car has 107k on it now. I'm going to drive it some more and see if it stays normal. I'll report back.

[Wr_guy]

Originally Posted by Wr_guy

Thanks Blazes.

Mine has done it twice when it was stone cold and it was normal after a restart. It seems most folks get this shortly after changing the trans fliud. I'm guessing the PC solenoid is hanging up from time to time..possibly due to dirt stired up in the fulid change. BTW I've changed the fluid twice, once at 55 and again at 103k...car has 107k on it now. I'm going to drive it some more and see if it stays normal. I'll report back.

I put another 1k miles on it and it has been fine since, so I'll leave it alone for now. Maybe the fresh fluid had the computer confused. All seems okay now.

[blazes9395]

Originally Posted by Wr_guy

Thanks Blazes.

It seems most folks get this shortly after changing the trans fliud. I'm guessing the PC solenoid is hanging up from time to time..possibly due to dirt stired up in the fulid change.

I agree, its most likly because of the new fluid cleaning internally. Glad to hear its working as it should.

[base1hits]

Blazes, you wrote "The other cause to this hard shifting problem can be caused by a bad or faulty EPC(Electronic Pressure Control) Solonoid. If it is found that this is the problem, then all that needs to be done is the EPC solonoid replaced and you should be good to go. This solonoid is found on the side cover, on the valve body." Can you please tell me where the valve body is located? Is it on the side of the transmission or on the side of the engine, somewhere? My tranny on my 2000 Venture (118K miles, fluid changed at 55K) is shifting hard, at whines at times as well. Thank you.