I have a suspicion that my transmission is overheating. I recently replace a leaky after-market radiator with a genuine radiator and new fans. My car's average coolant temperature dropped by 2-3 degrees and it hasn't gone over 95°C/203°F. I've made 3 or 4 long highway journeys (6 hours each) without problem.

However, on two occasions over the past few weeks, my transmission has been very reluctant in upshifting, it'll go up to 3,000 to 3,500 before changing gear. This has only occurred when it's been in heavy traffic. My transmission was rebuilt about 12 months ago. The oil isn't low, nor is it burnt (according to the transmission people who checked it yesterday).

I would love to find a cost effective method for checking the transmission cooling temperature and was hoping I could do this via an app. My Torque app doesn't seem to have the sensor required to do this.

Any advice or suggestions welcome!

Hello Troy,

I guess the answer hinges on whether the 'box itself contains an appropriate sensor. Using the Torque app or other ubiquitous OBDII scan tool, these can only report data available to acquire. However, check the wiring diagrams / pinouts for the TCM section, because that control module surely checks internal temp as a potential trigger for fail-safe limp mode and warning message. I have never sought what you are after via either B/T and Torque or via my Mongoose clone, but I do suspect that the dealer specific diagnostic package may be worth exploring.

Best wishes,

ANY Jaguar with a W5A580 will ONLY display gearbox oil temp IN GEAR.

P.S.
The gearbox oil temp sensor is incorporated in the CONDUCTOR PLATE.

The sensor exists, it's just a matter of finding the most cost effective way to access it as I believe many of the apps (such as Torque) may have limited access to the data.

Hey Motor, thanks for the info - during my search I did come across (via a post by @acuifer( the requirement to have the vehicle in D or R in order to receive the transmission oil temp data otherwise it falls back to the coolant temp.

Do you know if the conductor plate is Jaguar specific or an standard MB part? (trying to find a part number).

Note: I've never had a transmission overheating/too hot message or any other performance issues.

To save money you can use TP (Torque Pro) but you'd have to figure out the (non-OBD) command to issue and the formula to convert the data.

Cambo / others have posted TP stuff for other jags and maybe one of those would work or give a clue.

Most likely need a "mode 22" command.

Failing that, use WDS etc (or connect to the existing wiring?).

As JagV8 posted yes. I have Cambo's TP custom PID pack for years now.

Here is the full original thread. It's all free and well worth the effort!
Jaguar Custom PID Pack
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ALL Mercedes 722.6 conductor plates will fit.
Some are made in China and some are not.

icarsoft lr v2 reader reads gearbox temperatures on ZF so it is very probable it will also read on MB box
you may also hang generic temperature sensor on box cooler hose, it maybe won't give you most exact reading but the clues should be fine

An IR contactless thermometer on the IN/OUT cooler lines at the gearbox connections will give a good indication of fluid temp.(the hotter one is close to the internal temp)

Unfortunately, these PIDs don't apply to the X308/AJ27.

I've spent some time searching, but can't find PIDs for my vehicle or, more specifically, the PID for transmission oil temperature

Hang this 10$ thingy on the pipe Motorcarman indicated , wrap a bit to isolate from external temperatures and hang display in cabin
You may also hang second probe past radiator so you will have a clue if it is doing its job properly
It is the cheapest and most comprehensive test you can get

I've got something similar from when I had a Saab 9-5. The Renna autobox had to be at the right temp to get the fluid level right, so that was the easiest way to check. I dropped it down the dipstick hole after turning the car off.

I just replaced the conductor plate yesterday on my 2000 XJR. I had something similar with occasionally the transmission holding on to first and then a hard shift when it caught up. I haven't driven it enough to know if replacing the conductor plate solved the problem but hoping that it's the speed sensor that's causing the delayed shift and a new conductor plate will solve the problem. The speed sensor seems to be a known problem with the MB conductor plate.

I refilled the transmission based on the amount I took out, 6 quarts were needed. I did check the level once up to temperature at the tip of the dipstick using a contactless thermometer - not exact but started at 81F before dropping. I was wondering if i needed to do anything more exact and had the exact same question.

The plate looks to be a standard MB plate and compatible with any other 722.6. There's plenty of videos on YouTube on the process. Only tips I'd add are that all the Torx bolts for the pan, valve body and solenoids are T30 and need to be at 71 inch/pounds. Nothing difficult just messy to do on jack stands and the valve body is a little heavy to maneuver into place. Only other tool needed is a 7mm socket on a 10 inch extension for the electrical connector retaining bolt. Getting the bolt to engage requires packing out the socket so that you can put a little pressure on the head of bolt as you turn it otherwise it won't engage with the conductor plate.

For PIDs, search the X100 forum, there is good information on the AJ27 with 5HP24 and W5A580
Transmission fluid temp. is accessible via USD service 0x22 with parameter ID 0x11bd. Send request over Canbus to TCM at ID 0x7e9, and response from TCM sent with ID 0x7ed
(double check relevant threads in case I fat fingered the numbers...)

I'm reluctant to go down the path of swapping our the conductor plate, although it has crossed my mind. I just think it's too much of a coincidence that when my crappy radiator got swapped out for a genuine radiator this problem arose. As a technician (in non-mechanic/electronic field) I do believe that two things can go wrong at the same time, however, in this case my gut instinct is it's something to do with the new radiator.

Thanks much chirpy! I use the custom PID packs but have never built any on my own. Glad to hear it is possible on the X100 cars.
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Thanks for the tip Chirpy, I managed to add the custom PID to Torque Pro and now I can read my transmission oil temperature in the app

I added it manually as a custom PID using these settings you mentioned on your X100 post.

• Name:Transmission Oil Temperature
• ShortName:Trans Oil Temp
• ModeAndPID:0x2211bd
• Equation:A-50
• Min Value:-55
• Max Value:180
• Units:
• Header:7e9
• startDiagnostic: atsp6\natcra7ed\natcaf0\n0110\natcaf1\n
• stopDiagnostic: atsp3\n
• scale:1
• minimumRefreshDelayMillis: 0

Yeah, it's a lot easier to read the tranny temp from an app. IcarSoft has a pretty
good handle on things such as that.