Questions for those who tow
All this being said, if anyone has a good ODB PID for transmission temp, that would be the easiest way to get the data. If not I think I'll get an icarsoft.
We're in a towing thread. Transmission temperature is absolutely good info to have when towing. Overcooking the fluid will destroy it, and you can show down or stop while towing if it gets too high. Don't assume that just because it's useless info to *you*, that it's useless to everyone...
All this being said, if anyone has a good ODB PID for transmission temp, that would be the easiest way to get the data. If not I think I'll get an icarsoft.
And yes, while I certainly agree that ATF temperature is definitely a factor that needs to be considered when designing a car, if your ML has the factory towing package it already has a larger transmission cooler. There have been ZERO reports of transmission / ATF overheating issues with the diesel MLs - so in that regard it is indeed useless information. You're not trying to tow with a RAV4 where you actually run the risk of killing the transmission, you're doing it with a diesel Merc that has been designed to pull over 7700 lbs from the factory (that's what they are rated for in Europe - the 7200 lbs rating in NA is because they assume that you're going to have occupants and/or cargo that make up an additional 500 lbs, but it is not the towing capacity per se). In other words, it is not something that you'd need to keep an eye on. If you are overheating the ATF and need to stop to cool it off, it's because you're pulling a 9,000 lbs trailer uphill in which case I would respectfully suggest that you're using the wrong vehicle for the job.
And, last but not least, a $20 OBDII Bluetooth dongle and a smartphone will show you what you want to know - so again, why hack the COMAND system on the Merc even if you insist on looking at data that you don't need to be concerned with?
Last edited by Diabolis; Apr 15, 2022 at 11:07 AM.
Shouldn't be too hard to sniff the PID from icarsoft after I get it I guess...Thanks for taking the time to respond. I'd encourage you to be more welcoming of newbie (like me) questions and perspectives, it makes the forums a friendlier place! If I already knew all the answers, I wouldn't need to be on a forum, right?
And yes, while I certainly agree that ATF temperature is definitely a factor that needs to be considered when designing a car, if your ML has the factory towing package it already has a larger transmission cooler. There have been ZERO reports of transmission / ATF overheating issues with the diesel MLs - so in that regard it is indeed useless information. You're not trying to tow with a RAV4 where you actually run the risk of killing the transmission, you're doing it with a diesel Merc that has been designed to pull over 7700 lbs from the factory (that's what they are rated for in Europe - the 7200 lbs rating in NA is because they assume that you're going to have occupants and/or cargo that make up an additional 500 lbs, but it is not the towing capacity per se). In other words, it is not something that you'd need to keep an eye on. If you are overheating the ATF and need to stop to cool it off, it's because you're pulling a 9,000 lbs trailer uphill in which case I would respectfully suggest that you're using the wrong vehicle for the job.
And, last but not least, a $20 OBDII Bluetooth dongle and a smartphone will show you what you want to know - so again, why hack the COMAND system on the Merc even if you insist on looking at data that you don't need to be concerned with?
There's a reason there is a transmission temperature gauge built into the dash on my Chevy truck; it isn't there for looks. The truck is built for towing and the gauge is there to tell the operator when to back off. Plenty of guys also add a cluster of gauges to the A pillar to monitor exhaust temperature, oil temperature, turbo pressure, etc...
To assume Mercedes designed a perfect system that never needs any input or monitoring is to trust the machine far too much, especially if a simple meter will inform the user when the limits are being pushed and you're thousands - or even just hundreds - of miles from home.
It bears repeating: transmission fluid temperature is a good thing to monitor while towing.
I also have torque pro. I wonder if it might be worth us ganging up and emailing the developer to ask if adding transmission temperature to one of his readouts can be done.
Last edited by rapidoxidation; Apr 21, 2022 at 12:58 AM.
There's a reason there is a transmission temperature gauge built into the dash on my Chevy truck; it isn't there for looks. The truck is built for towing and the gauge is there to tell the operator when to back off. Plenty of guys also add a cluster of gauges to the A pillar to monitor exhaust temperature, oil temperature, turbo pressure, etc...
To assume Mercedes designed a perfect system that never needs any input or monitoring is to trust the machine far too much, especially if a simple meter will inform the user when the limits are being pushed and you're thousands - or even just hundreds - of miles from home.
It bears repeating: transmission fluid temperature is a good thing to monitor while towing.
I also have torque pro. I wonder if it might be worth us ganging up and emailing the developer to ask if adding transmission temperature to one of his readouts can be done.
A transmission fluid temperature gauge is a good thing for those that care about their drive train. YMMV, it is a free country.
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