Topic: 4T65E W-Car Tranny Mystery

[99dej]

I've got a '01 Olds Intrigue with the 3.5l V6 Baby Northstar/4T65E combo.  Love this car!  I get outstanding fuel economy, and when I use the right oil, no oil consumption.

But, I noticed a couple of things a few weeks ago - first, my speed limiter has gone by the wayside.  I've got the Autobahn package on this with the H-rated tires, so it would top out at about 180km/hr.  2 weeks ago, I was up past 220 with some pedal left - not counting speedo accuracy. 

3 weeks ago, driving it for about 45 mins, got into the city, and noticed harsh shifts.  Stopped it, shut it down, turned back on and everything was ok.

Then, after driving the car this past weekend for about 1.5h on the highway, we turned off on a side road, and noticed we now had no first or second gear.  Stopped the car, shut it off, turned it back on, checked the oil color, checked for filings, and smell - it was all ok.  Got to our destination, stopped the car for a few hours, and when we got back in, everything was fine.  Took it out yesterday, no problems shifting or driveability.

Took it to a GM tech with his own scanner at home, no codes.

I don't know if these things are related, but these are the only extraordinary things I've noticed.

I'm stumped.  Anyone have any ideas?

[weebl]

Sounds like a TCM issue of some sort, likely software related.  Maybe our local GM expert Barrie can shed some light on this.  He'll be around shortly.

Too bad GM got rid of the Intrigue, I thought it was the best car they had on that platform.  Got a chance to drive an '03 once (not sure which powertrain it had), and it was nice!

[barrie1]

I am guessing the Homogolater Valve which used to screw on the outside of the tranny and maybe still does on this box.Possibly it  is starting to leak a bit of fluid into it. None allowed at all to work correctly. When they start to go they usually start to act up in the 1st gear shift and sometimes in the reverse shift as well. How many miles on this vehicle and when was the tranny serviced last Please? Could just be  a service may help a lot. 

[99dej]

First, answer - there is about 130kms on this, and no service - I was going to do it at 160km's as this sees mostly highway usage.  I will do the service, flush actually.  I've been doing this by unhooking the cooler lines, adding, etc until the color changes, usually about 8-10 liters on the pickup.  Assuming this can be done on the Intrigue.

Today, however, I stopped for gas.  Got back in the car, and the SES lite was on, the Slippery Road symbol, and the Traction Off lite.  Was on my way past a GM dealership and had them hook up the scanner - no codes.  Did my service call, got back in the car and no lites.  Not sure if the tech cleared the codes or not.

So, I'm thinking I've got a PCM issue because of the lites on but no codes found.  Thoughts?

[roadrunner]

Barrie,

These PCMs can be reprogrammed can't they? Perhaps it needs to be updated. That possible?

[99dej]

mrs. jed went around the corner after starting up the car and it died on her.  Started right up again, and no problems.  I think I'm going to call a priest.

[barrie1]

Roadr is correct in that they can be retuned via computor. As you gone past the Speed limiter you may have upset the balance preset in the tranny from the factory. Could be a combination of reprogramming and a good service will tell you the whole story on this tranny. These are generally a well built product and will  last much longer then this when they are properly maintained. My guess is a reset and a flush will set things right again. 

[99dej]

K - I was under the impression that if the lites are on and noboby's home, the unit should be replaced.  So, a simple re-download of the PCM from the Tech II should fix it?  (along with the service).  I guess thats certainly the easiest and cheapest to start with, being as a new PCM is almost 400 beans.

Cheers!