HELP Limp Mode 97 GC 3.3 engine OBDII P01698

I have a 97 GC 3.3 engine 187,000 miles I have maintained the Trans religiously..pan drop filter & fluid every 30,000 miles. Last weekend after driving 150 miles with no problems, stopped at a store for 20 mins, got back in the van drove 1/4 mile and when I went to acclerate away from a red light..engine over-reved (neutraled out) only able to run up to 2nd gear after that. Limp Mode...1st time it's ever happen. Plenty of fluid...pretty red...just a ltrace of a burnt smell

I manage to find a AAMCO trans shop open on Saturday afternoon they take it in, I leave the van with them and get a ride back home 150 miles. Guy tells me it's got to be internal..$300 to drop it crack it open & estimate...he calls me back on Monday and says..he got a code P01698 (no communication between the trans and the TCM.) and now he's thinking it's electrical..and he's not going to take the tans out and apart until he can be sure it's not external electrical problem. There is no grinding and it runs okay in 1 and 2.

It's now 2 days later and he's still stumped..says he has calls into a AAMCO tech help desk, says he tried a similar TCM from another GC, he's switched the ETAX relay, he's looked at the BCM..I've been trolling the web looking for ideas..I've even e-mailed him a link to a trans-rebuilders website. He still hasn't pulled the trans, (which I am okay with..until he's sure it's internal)

Does anyone who has had a similar problem have an idea where we should look?

Is there any relay, fuse or fusible link that might be a problem?

I did change he struts and had the van aligned the week before...I mention that because the tech was under the front of the van doin his thing etc...damaged some wres? (although it ran fine all week and 150 miles first on the day it crapped out.

I think I've seen some thing relating to the BCM Body Control Module...and I do on rare occasion have ghost wipers, or power locks that don't work for a time or two.

I've seen some things about bad connections corrosion at the Power Center (fuse box) under the hood.... And a thing or 2 about connections on the dash/instrument panel
I wish it was sitting in may garage at home and I could try different fixes myself.
Any ideas welcome Spit

Have the connectors to the input and output sensors, also the connector going into top of tranny by the input and output fluid lines. Have the input and output sensors every been changed???

Take a close look at all the wiring harness connections under the battery tray. Acid drips on them and corrodes the whole harness and the others close by. I had to rewire mine completely (cut and splice) a few years ago due to the pizz-poor design and location. A new harness is over $1000, so don't go that route.

Hey Guys...turned out this cost me $1600 to have the trans rebuilt. I asked for and got the old parts, I'm going to show them to a friend of mine who runs a shop and see if he thinks that they needed to be changed...IN additon to the seal kit they put in a couple of hubs a torque convertor also they changed the igniton switch and the PRNDL switch..both sensors and the solenoid pack

Turns out the the Aamco tech tells me that my 97 GC had a 95 TCM in it!! I called the dealer and their records show that they replaced the TCM in march of 1998. According to
the Aamco guy this mismatch between the TCM and the PCM prevented his reader from properly analyzing the transmission... I left a voice mail for the service manager telling him that this errant parts replacement had cost me $$ for the extra labor it took AAmco..haven''t heard anything back as of yet.

Thanks for your replies..yes I had changed the speed sensors, they came with a new solenoid pack that I replaced 30K miles ago. I did not have a chance to look at the wiring under the battery. It sounds like the shop was on the up and up with me. I half called the dealer so as to see if what they told me on the TCM was right.


spit