Tow Mode

namsam1106_98185047

We are towing a [email protected] 320. After about an hour of towing, especially uphill, our indicator goes from blue to red. Sometimes it goes back to blue when braking or stopping. We have only had one significant tow, we are now on our return trip home, and it is doing it again. Also, we have to manually put the car in tow mode, as it does not automatically do so when connected to the hitch. Anyone experience this?:

namsam1106_98185047

It appears the blue tow mode light will remain on if auto headlights is turned off.

However, still need to manually turn tow mode on from console. It does not automatically when connected to hitch.

sosmerc

Just curious, what does putting the car into "tow mode" actually do?

Tropopause

Actually the OP is referring to Trailer Mode which adjusts parameters for Model X pulling a trailer. Tow Mode is actually for pulling a Tesla onto a flatbed.

sosmerc

Thanks ! Good to know as they are clearly two completely different modes. I just got through reading somewhere that you might want to use "tow mode" when cruising through one of those auto car washes....similar to putting an ICE into neutral.

drdavelynch_98126905

I would just put it in neutral for the car wash.

Uncle Paul

Car may switch from neutral to park if someone is not in the seat.

kmclancy_98134228

Can anyone answer the original question? while towing a trailer, there is a trailer Icon on the Dash, the icon is normally Blue but seamanly randomly turns red. My first thought was maybe with the brake lights, but then it was red all the way up a hill, so no brakes. And it was blue stopped at a light.

Y_Doesit

Same here on my Y - can go hundreds of miles in blue, then red blue red blue seemingly at random. My frunk open warning does the same thing. I noticed the car sends a low V signal to the trailer lights as pulses, presumably to tell if the trailer is connected. I have very efficient LED lights maybe not enough resistance???

mbirnie51

To ALL...Please read the owners manual before you ask questions. Towing with Model X is explained on pages 94-104 of your manual. On page 97 it states that the icon colors change due to certain conditions. Please go to the manual to see what a RED icon means. If I told you in this reply, you might not read all the other VERY IMPORTANT information you need to be aware of for the safe practices in towing, which will protect your vehicle and other drivers on the road.

andrew_93384936

A couple possible explanations... I noticed on a Model X I rented that I always had to turn Trailer Mode on manually every time I started the car. It wouldn't come on automatically when the trailer connector was attached. However, I was using a 7 pin to 4 pin adapter since the cargo trailer I was towing came with a 4 pin. That may have prevented the Model X from properly sensing the presence of the trailer.

As for my new Model Y (2021) it does turn on automatically when the 7 pin is connected, but it's also connected to a travel trailer that comes standard with a 7 pin.

As for what Trailer Mode does... among other things, it supplies power to the 7pin. Your running/brake lights on the trailer won't work without it. Also autopilot/auto-steer is disabled. Traffic aware cruise control will still work. I imagine it also ignores data from the rear facing cameras, since the trailer would likely confuse it. This is why some autopilot features are disabled too. Also, I think the vehicle optimizes power, traction control and other driving dynamics to compensate for the trailer.

As for the Red icon problem, I noticed that on my Model Y it switches from Blue to Red randomly. Now the manual explains that the Model Y senses a faulty electrical connection and that some or all of the lights may not be working on the trailer. But both my Model Y and travel trailer are brand spanking new so I don't think it's a faulty connection. HOWEVER, I remember reading somewhere (or someone told me) that the icon might also turn Red if the trailer is drawing too much power from the car. This actually makes sense in my case. If I'm parked and the Model Y lights are off, then I always see a blue icon, but when I turn on the parking lights (or headlights) which supplies power to the trailer making it's lights come on too, I sometimes get a Red icon. However if I'm plugged into shore power, the light will stay blue. I'm assuming cause the systems are pulling power from AC and not the trailer connector. Sure, the running lights are likely still powered from the 7 pin, but your trailer can also use power from the 7 pin to charge its battery or run other stuff. It's easy to imagine this could draw too much power. And it explains why it goes on and off, as the battery goes between charge and float, or as other things in the trailer turn on and off, like fridge, fans, etc.
I also noticed that the icon typically isn't Red during the day (even though shore power to the trailer is unplugged) and I think that's because my solar is charging the trailer battery instead of relying on the 7 pin to do it.

Anyway, do some tests around that theory and see what you get.