Pre-Collision Assist Not Available - Warning

[WingShot]

My 2021 Ranger XLT Tremor is equipped with the factory installed tow package, Firestone Ride Right Air Bags, and an after market brake controller (Draw-Tite). I am towing a hybrid, off-road camping caravan with a GVWR of 5732 pounds. Towing the camper for a weekend trip, 150 miles each way. Mostly two-lane highway with a couple easy mountain passes with a few steep sections.

About 50 miles into the trip while ascending one of the steep sections: the Pre-Collision Assist Not Available warning pops up, it cancels Tow Mode, the transmission freaks out, and the “wrench” warning light appears.

After stopping and re-starting the truck, I get the same warning message and it won’t let me select tow mode. Decide to let it sit a few minutes and maybe re-set itself. In the meantime I check what I can and reseat the electrical plug on the trailer. Truck restarts normally, Tow Mode selects, and we are back on the road. We arrive at our destination with no further issues.

On our return trip it happened two more times. After the third time I also get the Check Engine Light warning. This time I deactivated Pre-Collision Assist in Settings before getting back on the road. Return home without any more problems.

Each time it happened while going up a pretty steep hill. The first two times it happened while someone was passing me on the left, but not the last time. I also towed a different camper a few months ago on the same route, with the same truck set-up, and had no issues.

With the Draw-Tite controller I understand that Pre-Collision Assist is not available. But I would expect it to just not work, not give me an error miles down the road. But maybe with this set-up I just need to disable that in settings? Also seems odd that I was able to do this same trip with no problems a few months ago. It was a lighter camper but I don’t think thats an issue here.

Check Engine light went away after parking and un-connecting the camper.

Any thoughts?

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[halligan1201]

Total speculation on my part that it has something to do with the angle of the camera and it not being able to see the road due to the hill plus the weight of the trailer pushing the nose up? Either way it sounds like making sure you disable it is the only solution.

 

[WingShot]

Total speculation on my part that it has something to do with the angle of the camera and it not being able to see the road due to the hill plus the weight of the trailer pushing the nose up? Either way it sounds like making sure you disable it is the only solution.

I like the creative thinking. Seems possible.

 

[Jason B]

My 2021 Ranger XLT Tremor is equipped with the factory installed tow package, Firestone Ride Right Air Bags, and an after market brake controller (Draw-Tite). I am towing a hybrid, off-road camping caravan with a GVWR of 5732 pounds. Towing the camper for a weekend trip, 150 miles each way. Mostly two-lane highway with a couple easy mountain passes with a few steep sections.

About 50 miles into the trip while ascending one of the steep sections: the Pre-Collision Assist Not Available warning pops up, it cancels Tow Mode, the transmission freaks out, and the “wrench” warning light appears.

After stopping and re-starting the truck, I get the same warning message and it won’t let me select tow mode. Decide to let it sit a few minutes and maybe re-set itself. In the meantime I check what I can and reseat the electrical plug on the trailer. Truck restarts normally, Tow Mode selects, and we are back on the road. We arrive at our destination with no further issues.

On our return trip it happened two more times. After the third time I also get the Check Engine Light warning. This time I deactivated Pre-Collision Assist in Settings before getting back on the road. Return home without any more problems.

Each time it happened while going up a pretty steep hill. The first two times it happened while someone was passing me on the left, but not the last time. I also towed a different camper a few months ago on the same route, with the same truck set-up, and had no issues.

With the Draw-Tite controller I understand that Pre-Collision Assist is not available. But I would expect it to just not work, not give me an error miles down the road. But maybe with this set-up I just need to disable that in settings? Also seems odd that I was able to do this same trip with no problems a few months ago. It was a lighter camper but I don’t think thats an issue here.

Check Engine light went away after parking and un-connecting the camper.

Any thoughts?

I am not sure that statement is true. IIRC, you should still get pre-collision, it just won't activate brakes on the trailer which could lead to jack-knifing. So, deactivate it if towing with a non-OEM approved TBC. Otherwise, the Pre-collision would deactivate as soon as a trailer was connected.

 

[WingShot]

I am not sure that statement is true. IIRC, you should still get pre-collision, it just won't activate brakes on the trailer which could lead to jack-knifing. So, deactivate it if towing with a non-OEM approved TBC. Otherwise, the Pre-collision would deactivate as soon as a trailer was connected.

Yes, that is how I understand the brakes behave. But if the pre-collision assisted brakes are still functioning on the truck, why warn that they aren't available? Why cancel tow mode and have the transmission freak out? There was no "pre-collision" event happening.

 

[D Fresh]

Did you try to read any codes?

Locking you out of tow makes it sound like you might have been in limp mode.

 

[WingShot]

Did you try to read any codes?

Locking you out of tow makes it sound like you might have been in limp mode.

Reading codes is beyond my current capabilities. Had an appointment at Brighton Ford all ready set up for Wednesday. So I'll see what they say.

 

[WingShot]

This old post sounds very similar...

https://www.ranger5g.com/forum/threads/pre-collision-system-warning-while-towing.5072/

 

[D Fresh]

Reading codes is beyond my current capabilities. Had an appointment at Brighton Ford all ready set up for Wednesday. So I'll see what they say.

Gotcha.

I've had really good luck there. Hopefully they treat you well, too.

If, for some reason you can't get it in I can help you read any codes via ForScan.

I'm betting if there are any stored codes they'll shed some light on what happened.

 

[WingShot]

Gotcha.

I've had really good luck there. Hopefully they treat you well, too.

If, for some reason you can't get it in I can help you read any codes via ForScan.

I'm betting if there are any stored codes they'll shed some light on what happened.

Thanks for the offer, I might take you up on it. I've been dragging my feet on ForScan but this may be the push I need.

 

[Jason B]

Yes, that is how I understand the brakes behave. But if the pre-collision assisted brakes are still functioning on the truck, why warn that they aren't available? Why cancel tow mode and have the transmission freak out? There was no "pre-collision" event happening.

I was speaking in general about Pre-collision. There something else going wrong with your system.
I don't tow but have had the Pre-collision unavailable warning. But that was due to heavy fog or rain, or dirty windshield. It cleared itself after a while.

 

[JDowns]

Total speculation on my part that it has something to do with the angle of the camera and it not being able to see the road due to the hill plus the weight of the trailer pushing the nose up? Either way it sounds like making sure you disable it is the only solution.

This seems to be the most logical answer. This topic comes up every once in awhile, and towing - hills seems to be in the equation. The camera system is calibrated and I would guess you are correct in that the mixture of the terrain and the trailer pushing the nose up leads to a situation where the camera system is outside the calibrated bounds.

 

[WingShot]

A quick update for those interested...

Disabling the "Pre-Collision Assist" was not the solution. However, I did get to Moab and 2/3 of the way back before the issue re-surfaced. Climbing the hill from Silverthorne up to the tunnels, it happened twice. But not again on that trip, and just returned from a shorter trip with no issues. It is difficult to nail down.

Fast forward to last week...I drop the truck off at Brighton Ford for diagnosis. They have the truck for five days and can't duplicate the problem. And said the computer didn't have any saved codes. Suggest the only course of action is to have a tech ride around with me while the trailer is hooked up and see if we can get it to happen. I ask when the tech had a week available, we could drive all over the Rocky Mountains and not see it again. Tough to see any practical way to accomplish that.

On a side note, it was a very frustrating experience with Brighton Ford. Very little communication, and what we had was defensive and argumentative. I have never been spoken to in such a way from a customer service representative. They have been strongly recommended in the past, maybe they guy was having a bad week. But certainly not inclined to bring it back to them for more "diagnosis".

Not sure how to proceed at this point.

 

[WingShot]

Gotcha.

I've had really good luck there. Hopefully they treat you well, too.

If, for some reason you can't get it in I can help you read any codes via ForScan.

I'm betting if there are any stored codes they'll shed some light on what happened.

Hi Doug, I sent you a PM.

 

[machinist85]

I just had the same thing happen. Did you get your truck figured out?

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