I'm having some issues with my 2001 Oldsmobile Aurora V8.

During a recent 10 hour drive, my car started hesitating while cruising at a constant speed. Once the hesitating started, it would continue until I let off the gas or accelerated heavily. Under normal acceleration or when maintaining speed, the hesitation would come back either right away, or within a couple minutes. I found that putting the car into 3rd seemed to smooth things out, so I drove it that way the rest of the trip (about 3 hours remaining). It still occasionally had issues though.

Later on in the evening after a few restarts, the MIL came in. I checked the codes and read a P0386 and P1860. I know P1860 is related to the TCC. I had the TCC solenoid replaced about a year and a half ago after the MIL came on for that. I never had any issues driving at that time, and this appears to be a separate (but possibly related) issue.

Also, about a year ago I had the car stall on me while driving slowly through a parking lot. After that, the MIL came on and I read P0385. Nothing else ever came of that though, and eventually the light went back off on its own. I've had the car stall a couple other times since then, usually when slowing down to a stop.

I took it in to the dealer today, and they said they were able to eliminate everything outside the trans. They were getting abnormal readings from the TCC solenoid on the scanner while driving. Their best guess is that it's the wiring harness, so they rough quoted me $1250 to open the trans up and replace the harness. However, they weren't 100% sure what the problem is, other than that it's inside the transmission.

Currently, I only drive short distances. I haven't noticed the problem much since the 10 hour trip, but it has come up occasionally. The few times I've noticed it lately have been when accelerating or going up a hill. But it hasn't been as bad or as reproducible as it was during the long trip.

So, I guess I'm wondering if anyone else has had issues like this, or has any better ideas on what the issue could be. The car "only" has 77k miles on it, so I'm curious on what would cause such an issue. From what I've read, the 4T80E has been pretty reliable other than the TCC solenoids having to be replaced.

 

It's not really the solenoid that has the problem...it's the leaking lock-up(tcc) circuit in the trans that causes the solenoid to be overworked, and fail. Simply replacing the solenoid will only delay the inevitable...the trans needs to be repaired, and the torque converter replaced. "Abnormal" readings from the solenoid doesn't give us much to go on. A solenoid can have a high/low resistance reading, and still perform fine. It can also have perfectly normal readings, and not work at all. A solenoid can be fine electrically, but fail mechanically. My bet is the solenoid is melting from being held "On" 100% of the time, due to the PCM attempting to stop the torque converter slip, which is actually caused by the leaking/worn seals inside the trans....
Not sure how to go with the "hesitating" thing...what do you mean by "hesitating"?

I don't see a reference to P0386 in Mitchell or AllData...do you have a code description for that code? I have a P0385 that is a crank position sensor....