1990 fails to shift out of first gear. Fuse Issue?

[GMFreak38]

Hey guys, this is my first post here, but I heard this is the place to ask and someone may be able to help me.

Here's my issue, I have a 1990 Park Ave that my father just changed the torque converter clutch solenoid in. After he got it all installed he took it for a drive and it shifted perfectly. He turned it off went inside and did a few things and went back out to drive it again and this time it wouldn't shift out of first gear. I can manually put it into second gear using the shifter, but that's the only way to get it out of first. I called a repair shop up and the guy seemed to think it could be a fuse for the transmission. He said it was in the dash somewhere on the passengers side in a box, but I can't for the life of me find it. He also said there may be a fuse under the hood that could be blown too. Does anyone here have any idea where this fuse is located, or am I chasing a ghost? Any help would be appreciated. Thanks.

[ZiggyPA]

I don't know if the problem is a fuse, but there are fuses hidden way below under the dash on the passengers side. You have to remove a panel for this (at foot height) it is next to the oil reset button.
There are also fuses under the hood, remove the panel under the wiper on the passengers side.

[maxwedge]

Make sure the plug on the trans is firmly pushed and no bent pins, also the vacuum modulator is connected. I would backtrack the work that was done, if it shifted before. Will it upshift past second manually? Is this a 4t60e?

[GMFreak38]

Originally Posted by ZiggyPA

I don't know if the problem is a fuse, but there are fuses hidden way below under the dash on the passengers side. You have to remove a panel for this (at foot height) it is next to the oil reset button.
There are also fuses under the hood, remove the panel under the wiper on the passengers side.

Oil reset button? Did a 1990 Park Avenue have this? Mine doesn't have the digital dash or anything. I found a grouping of 5 or so fuses ranging from 7.5 to 20 amps right underneath a bunch of relays behind the glove box. The heater ducting under the dash is the only panel I can see that you could remove. Is that what you are talking about? I'll have to look under the hood and that panel.

[GMFreak38]

Originally Posted by maxwedge

Make sure the plug on the trans is firmly pushed and no bent pins, also the vacuum modulator is connected. I would backtrack the work that was done, if it shifted before. Will it upshift past second manually? Is this a 4t60e?

I checked the black pin connector on the front of the transmission and it seems ok. where would I locate the vacuum modulator? They did have to move a lot of stuff around, a vacuum line could have been knocked loose. It shifts into 1st 2nd manually via the gear selector. How would you test 3rd and 4th?

[GMFreak38]

FYI it's a THM440T4 AKA the 4t60. It is not the 4t60-E. And I have no idea why it suddenly turned to bold font...

[HotZ28]

The first year for the 4T60E in the PA was 1991, if the tranny is OEM, more than likely it is the TH440-T4/4T60 with a throttle cable control shift valve. BTW, have you adjusted the trans throttle cable?

[GMFreak38]

Originally Posted by HotZ28

The first year for the 4T60E in the PA was 1991, if the tranny is OEM, more than likely it is the TH440-T4/4T60 with a throttle cable control shift valve. BTW, have you adjusted the trans throttle cable?

We did not adjust the throttle cable. Some I talk to say it's the fuse and others say that no such fuse exists. I don't know what to believe anymore...

[maxwedge]

There is no fuse for the 440t4.

[GMFreak38]

Originally Posted by maxwedge

There is no fuse for the 440t4.

Didn't think so. We let the car sit overnight, wiggled the throttle cable and suddenly it decided to shift. So who knows what happened. Now I have another issue. The heater won't blow anything except hot air regardless of setting and the defrost vents don't work. I must have touched something in the dash when I was hunting for the invisible fuse. *sigh*

Of course the reason why we replaced the solenoid is for shuddering and that's still there. The only way to get rid of it is to disconnect the tcc solenoid completely, which apparently causes major wear in the transmission?

[HotZ28]

Originally Posted by GMFreak38

Didn't think so. We let the car sit overnight, wiggled the throttle cable and suddenly it decided to shift. So who knows what happened. Now I have another issue. The heater won't blow anything except hot air regardless of setting and the defrost vents don't work. I must have touched something in the dash when I was hunting for the invisible fuse. *sigh*

Of course the reason why we replaced the solenoid is for shuddering and that's still there. The only way to get rid of it is to disconnect the tcc solenoid completely, which apparently causes major wear in the transmission?

How do you know that the shuddering was caused by the TCC? Have you eliminated all other possibilities like secondary ignition misfire? Check the vacuum lines under the dash to see if you pulled one loose.

[GMFreak38]

Originally Posted by HotZ28

How do you know that the shuddering was caused by the TCC? Have you eliminated all other possibilities like secondary ignition misfire? Check the vacuum lines under the dash to see if you pulled one loose.

I assumed that the shuddering was the TCC when I disconnected the wire leading to the solenoid and it no longer shuddered when shifting into overdrive. Now though I've read that shuddering when shifting into or out of overdrive can be an ignition issue, so disabling overdrive would only hide the issue not resolve it.

I also read that you can help eliminate the transmission by torque braking the car. Upon doing this it acts as though it's skipping (which it seems to do at low speeds or under light acceleration to begin with).