transmission problem

[jonflies]

Have had my 99 for almost 50k miles and have had this issue at least three times so far. Warm or cold, driving in town, it starts shifting real hard and running weird. I pull over, shut down, wait 30 seconds and restart. Everything fine. After a few times of this on the way home, the first time I pulled all the external connectors on the trans, plugged them back in restarted and it did fine for some time.

Second time, the local shop put it on their diagnosis unit and then reset the codes. I cannot remember what the codes were, but they "didn't make sense" to the mechanic.

Third time, I put it in low gear, only to have the transmission shift hard on by itself. I took it to the Chevy shop. (I don't want to hurt anyone's feelings but I don't usually use them first because I don't think they don't get enough of the shop fee to care about me.) They saw codes (again I forgot to write them down) reset them but couldn't get it to repeat. The tech pulled and pushed all of the connections too.

Has been running fine for at least two weeks, but between this mystery and reading about all of the cracked blocks I'm ready to sell both of my burbs and cut my losses, except I like the sound when they run.

Any ideas? (besides selling my trucks)

[jonflies]

Called the shop this morning and asked them to pull my file for the trany codes. It was a P1810 and had "tst errors".

After reading another post, I checked my trans cable harness, and as suspected, it was pinched between the cooler lines and the body. And yes, mine was made in Mexico. Verified with the shop.

[rjschoolcraft]

Were there any bare wires at the pinch?

[332bill]

Jon as I was reading your post I was thinking that you ought to check your transmission harness for pinching. I got down to your 2nd message and that was it. It looks like this problem is epidemic on 99 burbs. I had 6 wires with copper exposed, but I never experienced any tranmission shifting problems. just the no start when the nuetral/park safety switch wire wore through. I am sure it was just a matter of time though.

Bill

[jonflies]

checked for exposed wires and none could be found. Today the transmissions shifted on its own all the way to overdrive, way before it should have been there, as I was only going about 35 MPH. Also very hard shifts.

[DA BIG ONE]

Originally posted by Jon:
checked for exposed wires and none could be found. Today the transmissions shifted on its own all the way to overdrive, way before it should have been there, as I was only going about 35 MPH. Also very hard shifts. There is a pressure switch manifold inside the pan has a plastic body, when it goes bad pressure rises to uncontrollable levels in effect self destruct mode, if you will. I would not wait much longer to fix it.

Some techs get confused because their scanners say manifold pressure switch, thinking it has something to do with intake.

I believe this may be your issue.

[ 02-28-2005, 06:15 PM: Message edited by: DA BIG ONE ]

[DA BIG ONE]

Further, when the pressure sensor manifold goes bad it confuses the controller about what gear it is in causing erradict, hard shifting, skipping gears, eventually grinding gears.......

[DA BIG ONE]

Originally posted by Jon:
Called the shop this morning and asked them to pull my file for the trany codes. It was a P1810 and had "tst errors".
. P1810: TRANSMISSION PRESSURE SWITCH ASSEMBLY MALFUNCTION (pressure switch manifold)

"Find another shop!"

[jonflies]

Finally convinced the shop to do something. They replaced a switch, a harness and a filter for only $400.00 What a deal. Hope it works.