Warning Lights and Faults After Driving in Snow...

[keithw1975]

We got our first decent snow of the year, about 10 inches so far, and I drove about 6 miles to my shop today. Nothing eventful happened, the roads were mostly unplowed. After staying there about 30 minutes I went out and started the truck only to be met with all kinds of warnings the moment I shifted into drive. I got the following warnings:
Trailer Brake Module Fault
Hill Start Assist Not Available
Pre-Collision Assist Not Available
Service AdvanceTrac
Check Brake System
Tire Low (All Tires had 31psi in them, but for some reason it said the drivers side rear was the low one)

I drove it home and it seemed fine, but every few seconds was sounding chimes and popping up the AdvanceTrac error over and over. The truck just turned over 40k miles and hasn't had any issues or warning lights since I bought it.

Any thoughts???

Sponsored

 

[Gros Ventre]

We got our first decent snow of the year, about 10 inches so far, and I drove about 6 miles to my shop today. Nothing eventful happened, the roads were mostly unplowed. After staying there about 30 minutes I went out and started the truck only to be met with all kinds of warnings the moment I shifted into drive. I got the following warnings:
Trailer Brake Module Fault
Hill Start Assist Not Available
Pre-Collision Assist Not Available
Service AdvanceTrac
Check Brake System
Tire Low (All Tires had 31psi in them, but for some reason it said the drivers side rear was the low one)

I drove it home and it seemed fine, but every few seconds was sounding chimes and popping up the AdvanceTrac error over and over. The truck just turned over 40k miles and hasn't had any issues or warning lights since I bought it.

Any thoughts???

Snow/water got in a plug somewhere... Put it in the garage and let it dry out...

 

[keithw1975]

SMH..If that is the case and it fixes it, I am still going to be frustrated. My new truck shouldn't be less reliable in hazardous weather than my 26 year old diesel RAM. Shouldn't the connectors all be water sealed?

 

[m_bt54]

Happens to me most snow storms usually waiting for things to melt or a car wash with undercarriage rinse will take care of it

 

[PCfordguy]

SMH..If that is the case and it fixes it, I am still going to be frustrated. My new truck shouldn't be less reliable in hazardous weather than my 26 year old diesel RAM. Shouldn't the connectors all be water sealed?

This is a known issue- and caused me all sorts of problems just like yours. Mine went into limp mode as I drove to the dealership. Water in the trailer plug basically shorts out the related modules, causing all the error codes. Ask your dealership to repair/seal the trailer wiring hookup and make sure all the modules are updated. My dealership did it under warranty.
*edit* - the faulty weather proofing typically occurs on the back side of the plug under the bumper.

 

[Gros Ventre]

SMH..If that is the case and it fixes it, I am still going to be frustrated. My new truck shouldn't be less reliable in hazardous weather than my 26 year old diesel RAM. Shouldn't the connectors all be water sealed?

There are many multi-pin plugs in this truck. If I were king for a day at Ford, I'd have one guy at the end of an assembly line whose job was to go over every plug in the truck and ensure each one was properly seated. They all have water-proofing features that will work well... But if one is not fully seated... well you get the idea. I had a bad washboard bounce a few weeks ago. I got all kinds of warnings and PIDs, then it went into limp mode. I carry a code reader so I read out the codes, decided they were not likely serious and cleared codes. Still in limp mode, pulled over, shutdown for a couple of minutes and restarted. Cleared codes again and all was well in the world. Nothing since. My experience in the Navy (submarines) is that these kind of things are very likely a plug or a ground fault somewhere. So crawl around underneath and checkout each plug. These things are sensitive to a loss of bits & bytes and such... Doesn't take much in the right situation.

 

[v8440]

SMH..If that is the case and it fixes it, I am still going to be frustrated. My new truck shouldn't be less reliable in hazardous weather than my 26 year old diesel RAM. Shouldn't the connectors all be water sealed?

I dunno, I have a '98 12v dodge dually. In terms of reliability I'd put it against pretty much anything ford or any other company makes. It would really be an unfair contest given the relative simplicity of a 12v manual trans drivetrain.

 

[sPHYNX_76]

Do they salt your roads? This will flare up any contact issues. After reading similar stories, in summer I disconnected my battery and put contact spray on the connectors at the rear of the truck as insurance. Salt water can increase conductivity around 10 times in comparison to normal standing road water.

 

[TRI-Five]

I am dealing with the same issue as yours. After driving in the slushy snow for a few miles, the first error code was the Pro Power had detected a ground fault and shut down the 120 volt circuits; after a few minutes, I got the same errors that you received;
Trailer Brake Module Fault
Hill Start Assist Not Available
Pre-Collision Assist Not Available
Service AdvanceTrac
Check Brake System
The truck is at the Ford dealership now for the second time for them to locate the problem. My truck is a 2021 F150 Lariat.

There is TSB -24-2020 that applies to the ground fault detected in the Pro Power Onboard system.

I will post the dealership has corrected my problem.

 

[PCfordguy]

I am dealing with the same issue as yours. After driving in the slushy snow for a few miles, the first error code was the Pro Power had detected a ground fault and shut down the 120 volt circuits; after a few minutes, I got the same errors that you received;
Trailer Brake Module Fault
Hill Start Assist Not Available
Pre-Collision Assist Not Available
Service AdvanceTrac
Check Brake System
The truck is at the Ford dealership now for the second time for them to locate the problem. My truck is a 2021 F150 Lariat.

There is TSB -24-2020 that applies to the ground fault detected in the Pro Power Onboard system.

I will post the dealership has corrected my problem.

Have them check the trailer wiring hookup while it’s in there. There’s a TSB for that also.

 

[keithw1975]

These roads were all snow covered, so I doubt salt was the issue this time. I went out today and sure enough, about half the errors were gone. Still have a check engine light and trailer controller module fault and the tire low error, but everything else went away. I drove it around town and all seems normal. I will be taking it in soon.

 

[5IVE 0HH]

These kind of issues are frustrating as hell

 

[turbopilot]

Connecter problem would be the first thought.

But also consider a possibility the the radar detector is obstructed with snow. I had the happen in a FreightLiner RV with adaptive cruise control. When the radar was obstructed it throw all sorts of codes, many seemingly unrelated to the adaptive cruise control functionality.

 

[lurcher79]

I have the same hill start assist warning after driving in the snow it even specified that it was a problem with valve relay - in the ford pass app. the problem has disappeared but should I still have the dealer check the weather proofing underneath? brand new 24' raptor. I know pre collision assist unavailable is just because of snow on the sensors I don't think you can do much about that when driving.

 

[TRI-Five]

Sorry it took so long to list what actions the dealership made and has hopefully resolved the problem. The dealer had a Ford Tech come on site and he made the following actions: Replaced the 120 Volt outlet and associated wiring to the first wiring connector located under the bed over the spare tire; he also reseated the wiring connector that goes to the tailgate. He indicated that several trucks have had issues with the tailgate connector not being seated securely after bed liners were sprayed in by sub-contractors. He also replaced the battery located behind the rear fold up seat. I had the opportunity to talk with him one on one and I asked why he replaced the battery. His response was that there had been a couple of problems with the battery voltage being slightly lower than specification and this had caused some issues.

I haven't driven is snow since they made these corrections, but I have driven in several severe thunderstorms and went through the car wash often. So far, (crossing my fingers), the problems haven't reappeared.

Sponsored