Key Fob issue

[azlambo]

I’ve got a 2018 Raptor. One of my key fobs stopped working. Replaced the battery twice. That’s not it. It will start the truck if put in the cup holder slot, but only if the battery has been removed. If I leave the battery in it, the cup holder slot thing won’t work. How do I get this fob to work with the truck again? The dash says “no key fob detected” with the battery in the fob. Weird!

 

[FordTechOne]

Sounds like the fob is damaged and will need to be replaced.

 

[j3ff]

@FordTechOne,

i have a 2018 SCREW that has been plaguing me with fob/starting/opening issues for months now.

i've looked at every conversation thread on the forum and i can't find a scenario that replicates my own problem with "Key Not Detected" problems as well as a strangely intermittent failure of the FOB on remote start, remote door entry and the truck sensing the touchpad on the door handle when i approach the car to open it.

for the avoidance of doubt, i'll describe the various issues i am having:

1) failure of key fob to unlock the truck doors when pressing the "open" button: this is intermittent, but seems to always happen if the truck has been sitting for a while. i need to use the manual entry/physical key to enter and then put the fob in the cup holder slot before alarm sounds.

2) failure of the truck to autostart after proper sequence of buttons are pressed on the fob: this again, is intermittent; i can drive the truck for a while and then autostart it from across a parking lot - or not.

3) failure of the truck to start with the fob in my pocket, though i may have been able to press it and successfully open the doors. in other words, the fob worked to get into the truck (intermittently) but the truck does not detect the key in the driver seat (in my pocket) and i need to put the key in the cup holder slot.

4) failure of the truck to allow me to shift into Drive if i have put it in Park and then walked away (e.g.: go to mailbox); requires me to put fob in cup holder slot.

i'll reemphasize the most puzzling part; this is all intermittent. it may work, it may not. it is not isolated to a single location (i.e.: in front of my house), it could happen anywhere.

NOTE the following:

1) i have replaced the batteries in both key fobs and used both at various times to try and troubleshoot if it was/is a fob issue. when they work, they work. does not seem to be dependent on distance or battery strength.

2) after reading one of the other threads, i put a brand-new premium battery in the truck. it seemed to make a difference when i first did it; then it went right back to same behavior.

3) the only aftermarket elements on the truck are BAJA DESIGNS fog lights (installed when i got the truck new) and they are all wired to the upfitter switches.

can you (or anyone else) give me some guidance based on the above? i have discovered that my local FORD dealerships (in STL, MO) don't seem particularly adept at fixing anything that a computer screen/scanner doesn't tell them to do directly...


thank you!

jeff

 

[Nex]

Test batter voltage. Unplug the fog lights and check for a battery drain. Look in the Ford Pass ap to see if it says that the truck is in battery saver mode. Battery voltage is a big thing on these.

 

[blwn]

Also make sure you reset the BMS if you haven't.. needs to be done anytime you replace the battery

 

[j3ff]

appreciate the advice, guys!

FordTechOne replied to a private message and also recommended the BMS reset and went on to say the truck likely still "thinks" the old battery was in place. i found the manual reset sequence (don't have ForScan) and the truck flashed to confirm the reset was complete.

i'll see what happens over the next few days, but no issues this afternoon after reset of BMS. hoping this was the missing link!


thanks again; really appreciate everyone in this community.


j3ff

 

[j3ff]

update: unfortunately, the BMS reset does not seem to have fixed the problem. i am wondering if my actual fob is failing or there is some other issue outside of the battery regulation? going to pull the "new" one out of my safe and pop in a fresh battery, reset BMS again and try that, along with aforementioned battery testing. the only thing about the battery test is that i know there is no vampiric loss and the battery is one-month old.

good times!

 

[Nex]

Have you replaced the main vehicle battery or had it tested?

 

[FordTechOne]

update: unfortunately, the BMS reset does not seem to have fixed the problem. i am wondering if my actual fob is failing or there is some other issue outside of the battery regulation? going to pull the "new" one out of my safe and pop in a fresh battery, reset BMS again and try that, along with aforementioned battery testing. the only thing about the battery test is that i know there is no vampiric loss and the battery is one-month old.

good times!

Have you actually measured the parasitic draw on the battery with an ammeter or amp clamp? If it’s drawing over spec it can result in these types of issues without affecting other systems. After 45 minutes of sitting with all doors/hood closed (or latches/switches locked/jumped) the draw on the battery should not exceed 50 milliamperes.

 

[smurfslayer]

This is a reach, but, are you sure that you put the batteries in the key fob correctly? Asking because you indicated at one point you had to remove the batteries and use the center console slot to start.

Next, when the remote fails, is it in the same geographic place and is there anything “atypical” about this place OR does it happen pretty much everywhere?

I had proximity to a fire truck complete disable the fob remote functions and had to use the console key slot.