I just removed a metallic colored metal box marked as follows. Is this the Transmission Control Module?

Small sticker on left side
30L
J334. 6157

Jatco sticker in middle
1X43-72401- LC
FJ6LUA0c. 3.0L
31036 PL115
ETC-J334. A1. 3Z23
It was mounted directly under another bracket with a metallic colored plastic box on the drivers sidewall, behind the fuse panel. Has 3 rows of 18 pins.
Thank you for any assistance.

 

JATCO is the gearbox manufacturer. If the module is marked as such then I would think you found it.
Why are you removing it???

bob gauff

 

I don't know if my reply got sent, so I am going to repeat it (I am on an I-PAD- not used to typing like this).
Thank you for confirming that the module is the TCM. The 2004 3.0L X-Type showed a "gearbox fault" while driving in a nasty Florida rainstorm. Because of a previous experience (also in a bad storm when it went right into limp mode at 70 mph), I travel with a code reader and was able to pull the following codes: P0078, P0778, P1111, P1643, P1793, and C1155. I was able to clear all but P1643, P1793 and the gearbox fault. I was advised by an on line mechanic that there may be water intrusion corrosion on the contacts as the windshield had recently been replaced. I have determined that there is no corrosion on the contacts and (without magnification) the electronic components look OK (I was an electronic tech about 40 years ago, but the eyes are weak). I am on vacation 1200 miles from home, so I don't have my tools or test equipment available. Looks like I will have to take it to a local Jaguar mechanic as my wife is afraid to drive it home with it in limp mode.
Thanks again for your answer, at least I examined the right part.

 

I spent the day at Jaguar while they checked out the "gearbox fault". They determined it was the TCM (which I expected thanks to you guys), but now that it shifts, it bangs as it engages the next gear. So I left it with them to check that out. Could I have damaged the tranny and caused this by driving it while it was stuck in 3rd for about 100 miles (mostly 50-60mph)?
Roughly, what should a used tranny cost? A rebuilt? This is in northern Florida.
Thanks for you input. You have been very generous with sharing your knowledge.

 

If it said gearbox fault then it was most likely in limp mode. Which depending on which fault code it will default to certain gears and raise pressure in the trans causing harder shifting.

There is probably corrosion on the "big chip" on the circuit board.

Did u open it up? If the dealer does not fix the water leak have them relocate the tcm to the dashboard main crossmember to keep the new tcm dry.

 

I never did find where the water leak is in the X-type. I had to wrap mine in a freezer back when i replaced it just to avoid having to go through that headache again.

 

Austinmartus is 100% accurate in my case! Bingo, man! I cleaned the circuit board, soldered one tiny contact leg from the big chip back to the board and tried it. At least it started, almost all the lights went off in the dash (except engine light), and came out of gear. Went for drive, it was jerky while shifting and half a mile down the road the "gearbox failure" came on again. I took it to the idiot dealer to have the codes cleared. Holy crap, I hope I never have to deal with that woman again, she is a moron! She was trying to tell me that they had to spend a day diagnosing the issue, etc. blah blah blah. After a week, I told her I knew what I was talking about, just clear the damn codes. they did. The failure showed up again in half a mile. I drove it home to bury it in the yard or plant a tree in it with the sunroof open. The shifting became smoother as i drove further. At home, I shut it off, pressed the computer reset button, dont' know what worked, but I went driving again and everything was perfect! Thank you for such a great post!

 

There is a computer reset button? Whete might that be, and will it help with my ABS light that has been on and off for almost a year mow!