I have a 2019 f150, and after running it through the carwash, it started to flash trailer connected, disconnected and the auto stop/start wouldn't work, I read about moisture getting into the trailer plug, so I sprayed WD-40 in it, and the connected, disconnected stopped, but the stop/start still isn't working?

Any thoughts out there?

T

 

Battery charge could be low. Auto stop/start is disabled by software if the battery charge is low. If you have an ammeter, check the battery voltage and see what you get. A fully charged battery should have 12.6 volts or more. Less than 12 volts shows a state of discharge. I'd put the battery on a charger in any case to ensure that it's fully charged - then see if auto stop/start returns to normal. Be aware that the truck needs to set for about 30 minutes after it's been driven before checking voltage. Voltage readings taken immediately after driving will be inaccurate and show a higher reading than the actual state of charge.

 

My AS/S (lol) stopped working this winter. Took it to the dealer yesterday for regular maintenance and I mentioned the s/s wouldn't work. They reset the computer and said that a variety of factors can make it not work including the battery having a low charge. I haven't checked the battery, but everything else works as it should.

 

My dad had the trailer connected/disconnected issue on his 2019 SD 6.7 lariat after going through a car wash. Took it to the dealer and found an issue with the trailer connection plugs in the rear bumper "added di-electric grease" no issues since. Doesn't it automatically disable auto start stop with a trailer connected? If so it could be your computer thinking you still have a trailer connected.

 

Heated seats on, A/C demand, and a host of other things as well can prevent A-STOP from shutting down the engine. Keeping a slight tension on the steering wheel will do this as well. Another member found a pin in one of the TCM connectors was not seated properly.

 

The auto stop start quit working on my 2015 F150 after driving through a puddle in the road. Nothing else was affected, but the auto start stop never worked again. So, maybe water has something to do with it?

 

This will, at best, temporarily fix the trailer connector issue. Clean it out with residue free cleaner. I use automotive electronics/MAF style cleaner. Then put liberal amounts of dielectric grease in both connectors to ensure water does not get back in.

 

There may be multiple reasons for *** to be disabled, including a bug in *** itself (I believe there was a software update for it a while ago).

If you charge your AGM battery with the _proper_ smart charger, you can get an idea about how bad the battery state was by checking how long does it take to charge it.

Also, I had an issue with the original battery. I suspected that it was not holding the charge quite well but after ~1 year of owning the truck (bought new) *** did quit working and even after charging the battery it would quit working again in a couple of days. Dealer replaced the battery under warranty and I do not have any problems since then, it's been over 2 years. The driving pattern did not change.

 

if you just filled the truck it may not work for a short time till the computer adjusts for the gas type. also if your A/C is on high it will not work.

 

One of the pages on the dash will tell you the reason that start/stop is not enabled. What does it asy?