Programbo

Hello all. My 1994 XJ has had some odd transmission trouble for years. 4.0L, automatic. Long story short it doesn't start shifting gears right until all the fluids or the transmission itself gets warm. Fluid, filter, linkage did nothing. I recently learned of the Transmission Control Module up under the dash and may swap that out but in reading about it I read that this module will use tempurature among other things to decide when to shift.

My question is...Where is this Control Module getting data from? I mean specifically what sensors are sending it data I could possibly check out. Thanks in advance for any input.

CCKen

Here's the '95 TCM connector pin out. Should be the same for the '94.

CCKen

Here's a pic of the solenoids. It shows the TCM pins for the '94 solenoids that appears on the TCM pin out.

cruiser54

Refresh the connectors under the hood first. Tip 10 in my pink link below.

Programbo

I shall check into all these things and refresh connectors. From the photo it almost appears the solenoids are replaceable without dropping the transmission?

cruiser54

Yup. None of it's too difficult.

Be sure to visually inspect the pins in the connectors.

CobraMarty

Not shifting when cold, OK when warm.
So, in the winter it take a long time to warm up and shift properly, and summer less time to warm and shift right?

I think all the innards and seals are partly gummed up.
In my 'commuter' Taurus, 195k, I had the same problem. Tried all sorts of things. Finally used 'Auto-Rx Plus' at www.auto-rx.com as directed and then flushed and filled to correct level with correct fluid. Trans works and shifts like new. IDK, snake oil? but it worked when nothing else worked. Saved needing a new trans.

ehall

What doesn't shift? 1-2? 2-3? All of them?

could be a sticking solenoid that doesn't break free until temps. you might have junk in the fluid, or the channels are scored. Run it for a while and then pull the dipstick and drip it onto a white plate so you can look at it under a light. If you can drain a cup and look at sedimentation that would be good too.

It wouldn't hurt to try dumping a bottle of Lubegard 60902 in there, its 50/50 parafin ester mix, really loosens stuff up, stuff isn't cheap so do it after the fluid test

CobraMarty

That 'ester mix' sounds like the Auto-Rx stuff.

Auto-Rx® Plus is a unique blend of three ester groups. A versatile lanolin ester is the key component. It is used for its deep-cleaning ability, and its function is to penetrate the surface of varnish and oxidized deposits.
The second component is an aliphatic ester. Its function is to strengthen surface adhesion of the host oil, reducing the risk of dry spots in the oiling system during the cleaning process. Aliphatic esters are also very resistant to oxidation, becoming an additive supplement to the host oil while the contamination is being removed and deposited to the filter media.
The third ester is a biodegradable polyol ester, which provides extreme pressure capability to the host oil. Utilizing heat, pressure, and flow generated within the oiling system, Auto-Rx® Plus safely and effectively dissolves deposits.

Programbo

Yes that's pretty much the way it goes exactly.

Nothing shifts. Until you get it warmed up a bit driving slowly for a mile or two you can step on the gas all you want and the engine just reves up high and you don't go any faster.

Changed the filter/fluid..Checked all the electrical connectors up by the dipstick and swapped out the modules between my '93 and '94 XJs. No effect thus far. I'll consider a flush next

ehall

Internal seal(s) damage. When fluid is cool the seal allows fluid to pass, then when it warms up the seal expands and holds the fluid like it should.