L322 Random Transmission overheat, even when cold

Well my turn again, I have a 2004 L322 4.4 which has had the transmission rebuilt not so long ago with all new cooling parts but I believe my problem is more electrical / electronic.
There are a few twists and turns.

I started the car on Friday morning having not been started since the previous day and I got the 'Bong' of death and 'Transmission Overheat' in the message centre.
I drove off normally and a few minutes into the journey, same thing but this time the warning stayed and it went into the the overheat program of holding onto the gear change until 4000 rpm.

I have found a few posts on various forums from Bemble / RRPhil detailing how to check the temp sensor resistance which I'll try tomorrow and I do have a suspect multiplug connection to the gearbox, which was a minor casualty of me removing my Transfer Box last year,.but in the meantime I connected up the All Comms and it showed no faults under the transmission ECU.

The only thing I have done recently is the day before the issue I had both front side light / indicator clusters out.
The other strange thing is the All Comms won't connect to the LCM ECU and I get the attached error which could be unrelated so I connected the Faultmate and that showed no errors for transmission but would connect to the LCM and showed a fault of no rear brake lights and front side light bulbs which both cleared.

AND, the other thing I stumbled across with the faultmate was one of the transmission solenoid pressures was really low compared to the others which can be seen on the attached.

Not sure if i should have started 3 different threads but any help is much appreciated as always.
Cheers
Andy

Your overheat problem does seem sensor related, I'm only guessing but I would start there and check the multi plug as it seems you have a comms problem. Cannot help you with the pressure reading but I would speak to whoever rebuilt your box.

Thanks Alan, the plug hasn't given me any problems but I will check it out and if I check the resistance at the ECU and at the plug on the box it should tell me if the plug is faulty.
As far as who built the box, that was me and a very handy mate and Bemble checked the valve body so I am very confident about the valve body being ok at the time

I'm no expert on the l322 but I can offer moral support

I'd also check the sensors if it's claiming to be over heating when it's stone cold it must be a sensor issue...

Thanks, the moral support I have found to be as important in the past as technical knowledge as if I have set fire to it and pushed it off a cliff in a huff then it's not getting fixed anyway
If it ever stops raining i will get out the multimeter
cheers

Is the sensor on the cooling rad as is on the P38 ?
mine kept ovehating and its the sensor problem

Thanks for the reply, I think it's part of the transmission internal wiring loom so can't be changed separately if my research is correct.
Fortunately Bemble / RRPhil has posted quite a lot of info around the net regarding it so I have found his part numbers and where to buy if it proves to be the problem after the wiring checks.

Faultmate should be able to track tranny temp...but if you has a sus plug, check that first esp. After all the rain we have had....

Measure the resistance to confirm as per Phils suggestions.

I believe solenoid 4 is for the torque converter LUC so will be different to the drive clutch figures as the LUC pressure is modulated to provide the 'continuous slip' function until you pass 56mph when it locks up which is when the pressure will be at its highest. all other times, this figure will fluctuate.

As for your light issue, I have a spare LCM you can try, whenI fitted it to mine I got a Brake lamp failure warning, but it might be worth a test to see if you can get comms via All Comms.

EDIT: Did you try connecting to other modules during your All Comms session?

Hi Ant, I think you are spot on with the plug and the rain as you probably remember the wiring loom plug onto the TB motor is a twist and lock type and I tried twisting it ACW and it was very loose so I twisted CW and it snapped back into position and prior to locking it home there was a gap around where the outer locking ring locates which is in need of a spot of grease I reckon. So far it has been ok today and the latter part of yesterday after I clicked it into place. so fingers crossed.

I was hoping there was a simple explanation to the lower pressure solenoid, I took the reading at idle and the oil temperature was reading at 68 deg. C as can be seen on the screenshot above and as that is from the transmission ECU I guess that's the transmission oil temp??

Regarding the LCM, it was only that and the navigation ECU that wouldn't connect, everything else was fine and the Faultmate connected to the LCM ECU OK but strangely that showed up as having both brake lights not working logged as a previous fault.

Many thanks for the offer, I'll see how it goes when I'm back on it next weekend as family and rain took place today so haven't had chance to check again.
I just read a reply to an email I sent to Storey Wilson yesterday and he said the LCM problem was with the All Comms and has been dealt with by another update which I haven't chance to check yet so hopefully i am back in business.
As usual LZ members keeping my spirits up until a solution can be found.
Thanks all, standby by for updates

We stand ready sir....

Stout fellows !!

(said in Melchett voice...)

Baah....

Permission for lip to wobble sir ?

Don't get me started on Blackadder !!

Permission granted Lieutenant.....

Stop - we could transcribe all night!

And that could be a fate worse than a fate worse than death... that's pretty bad.
I'm done mate..

holidaychicken said:

And that could be a fate worse than a fate worse than death... that's pretty bad.
I'm done mate..

Click to expand...

Carry on carrying on that man.

Cheers bud