Hi, I need checking one 6HP26 gearbox Tcm on bench... I see is not a terminal device in the can bus, I tried to connect it on bench using 60ohm resistor and Jlr software can't see it... I think instrument cluster is necessary beacouse it's the gateway... Is it correct?

Im not sure Tcm is the problem, just want to be sure at all, but I have one doubt in the event tcm had to be changed...I know tcm is part of the Cas system in BMW cars, and it's necessary to adapt it. Is it the same for 2005 Jaguar? I read contradictory things about it... Car is Jaguar X200 S-type 2005 2.7 V6 diesel.
I know there's new tcms at good price out there, just want to know if second hand ones are an option.

Thanks a lot!

 

If you use Search I think you will find no-one ever had one fail and so there will not be much chance of useful answers beyond the fact they appear reliable.

 

Thanks for answering me. I see what you say. I think it maybe is working by measuring voltages on can pins and observing that it consumes about 250ma when powered on...but tcm is not reachable with on car diagnosis.. All other modules are responding but tcm and cpm...
I see 12v and ground on the cable connector that goes to tcm... Can resistance in bus is 60ohm...can voltages are right..

Can somebody provide me with cluster pinout please? Pinout in wiring diagram that I have (2002.5)is not correct... It shows 3 plugs... My cluster have two 32pin plugs, one blue and one black.
​​​​​​I need power, ground, and can pins only.
Thanks

 

I read those tcm's are prone to failure if reflash software or reset adaptations due to a bug in both IDS and SDD...so if previous garage tried it, maybe tcm is corrupted and beacouse of that the no comm problem.
I tried connecting it on bench with 60ohm,120ohm and no resistor, all with same result.
A friend of mine told me tcm is not part of the immo and can be just swapped with same tcm if it is from same model/year/engine...


​​​

 

We've never found that to be true so I would be very doubtful about that claim. There's a lot of false info around.

Maybe post where you found it.

 

I read in some threads in MHH auto forums.
Tcm is not responding on bench, I used pinout from S-type wiring diagrams, used 60ohm resistor, 10A PSU, Jlr SDD 160... Software can't see TCM.
CAN pins voltage are both 2.5, so it is not trying to communicate, bus is at idle.
Tcm is not burnt beacouse it consumes 250mA when powered on through wake up signal. It seem data corrupted/erased problem.

 

No-one ever seems to have needed to replace or test a TCM along those lines in any of the Jaguars as far as I can find.

Any time I'm the only person doing something I wonder why and could I be up a blind alley LOL

 

Ok, and then...
Do you have an explanation why it don't communicate on bench please?

 

You're doing something wrong, I suppose. How can I possibly guess?

 

LOL is that all the help you are going to give? Don't tell **** to me if you are not going to help, it seem you only want trolling my thread?
I bench testing and programming modules all day sir, so not, I didn't do anything bad dear...
I got another second hand tcm yesterday, it connects on bench perfectly, so, yes, tcm's can go bad, like everywhere under the sun, despite it is in a Jaguar car......
Thanks for nothing sir.

 

It is interesting to know that the TCM will work as a standalone item for bench testing etc.
I had thought that they needed to initialise with the other modules on the car at power up via the can bus and serial coms to function at all.

Did you try to run the Jaguar SDD software on the car before removing the TCM? This may well have detected the fault without the need for bench testing anything.
Again it would be interesting to know what if anything was flagged up on SDD on a car with a faulty TCM.

Mellow

 

Hi,
I used cluster and ecu for bench testing it.
SDD did not show anything with tcm connected to car, just module not responding, and dtcs of no comm with tcm in some modules.

 

'Module not responding' etc on SDD does not help much!
But I guess with hindsight now you have tested them on the bench it does sort of point to a faulty TCM, and it is well worth knowing if same thing comes up again on SDD.
So the cluster and the ECU are needed to get a functioning TCM, I thought this was the case, but I was not sure.
This is all great info and well worth knowing going forward.
Thanks.
I guess as our cars get older we are going to start to find more unusual faults like this faulty TCM along with all the more common ones that are already known.

Mellow

 

Thanks for answering me and excuse me for late response.
I did more tests and it's possible to connect TCM alone, gateway is not needed. It can connecting even with a 120ohm resistor instead of 60ohm, so TCM have to respond even if ECU, that's a terminal device, is down on the can bus.
My diagnosis of this problem lead me to think it's due two possible reasons:

-Tranny temp had affected data exchange within TCM causing device is not able to boot and working correctly. Excessive heat can also damage TCM hardware, but I think not in this case beacouse device is waking up and consuming 250mA of power(good tcm consumes 320mA,so not far from it).
This car had a coolant leak and was driven anyway, so that is probably the root of the problem among 15 year old device electronics not liking so much increased heat.

-Previous garage/owner tried an adaptation of TCM values and it failed, bricking the unit corrupting its data. One tech said to me adaptation process is a risky thing to do it in these cars, best clearing values and let TCM to learn itself, not using sport mode next 60 miles.

My conclusion about how I will diagnose gearbox fault problem on these cars next time is by connecting to TCM plug directly and see if it responds. That can saving a lot of time by not checking a bunch of other things that can be related too.

Hope this info can help somebody. Excuse me for my bad English, it is not my native language.
Trans girl salute you. Cheers

 

No problem, no need to apologize. Your English is fine, much better than my Estonian. No issues understanding anything you've said.

Well, until that. You might be better off to use the whole word transmission in the English speaking world. The shortened "trans" usually refers to transgender, which I don't believe you meant...

And now back to our regular conversation.

 

Thanks for answering me.
Good to hear my English is understandable!
Well...i know about trans word, I play with it, I use it beacouse transmission, but I use it too beacouse I'm a transgender girl. I hope that won't be a problem for some of you,it is not a problem for me doing anything I want in this life, brave girl salute you, Cheers!

 

And I fell for it. You got me good, hope I didn’t embarrass you. I thought it was just a language thing.

Reminds me of an issue I once had with a coworker. (I’m an airline mechanic.) English is not his native language. He requested help to change a tire because it was flat. Several others and I thought he meant it lost air pressure. When that happens, the manual is very clear the adjacent tire must also be replaced, even if it looks okay. This is not uncommon as the remaining tire was likely overloaded, supporting all that weight by itself, and may have hidden internal damage.

I offered to get two tires but he insisted we only needed one. This seemed very out of character for him, as he was very conscientious. We went back and forth (still in the office) and our other coworkers backed me up that both tires needed replacement. After several minutes of this, we finally realized he meant the tire had a flat spot, not that it had lost pressure in the common meaning of a flat tire. Big difference, and the adjacent tire was fine.

Oh well, pardon my long boring story. I’ve got another one about the time I asked a one-armed man if he needed a hand (true story), but I should probably stick to discussing cars before making an even greater fool of myself.

 

No problem at all, thanks anyway.
Your history is not boring, it is very welcome
Thanks for your words.
Regards