HELP! No Key Detected

[MAMiller44]

Hey guys, been a while since I’ve been on here but need some fast help before my 6 week trip to UT/AZ next weekend. Out of nowhere this morning I’m having an issue with no key detected warnings, here’s what I’ve gathered:
- It applies to both fobs, I replaced the battery in both so it’s not the fob(s).
- Keyless functions on handles still work fine.
- Remote unlock, lock, start, tailgate release, etc still work fine.
- The “emergency” spot for a dead fob under the cup holder does not allow me to start the truck.
- Pretty much if I put the fob anywhere in the truck other than the back seat( yes you read that right, sitting on the back seat), I can’t start the truck.

Anyone have any idea WTF is going on? I had read somewhere that the transmitter is near the third brake light which is why I experimented trying to start with the fob closer to it.

 

[isis]

Calling @FordTechOne on this one. He knows where the antennas are and how to troubleshoot just about any system on these things.

 

[MAMiller44]

Calling @FordTechOne on this one. He knows where the antennas are and how to troubleshoot just about any system on these things.

Good looking out! Fingers crossed @FordTechOne has an answer. I do have an appt at Ford tomorrow but this is the same dealer that took 4 tries to properly swap a headlight so I don’t have much faith and would rather try to chase it down myself simultaneously.

 

[FordTechOne]

It's very unusual to have the backup slot fail. There are 4 antennas that activate the passive key; center (also functions as backup), rear, and one in each door handle. When the Start/Stop button is pushed, the BCM activates the antennas, which send out a low frequency signal. If the key is present, it activates, and transmits a high frequency signal to the RTM. The RTM then sends the PATS ID to the BCM over a private bus.

Since the rear antenna is working, that indicates the issue is not with the passive key or the RTM. The door and center antenna do not share connectors or circuits, so it sounds like it may be a BCM or radio frequency interference issue. Are there any aftermarket electronics in the truck, or has anything been wired into the BCM?

 

[MAMiller44]

It's very unusual to have the backup slot fail. There are 4 antennas that activate the passive key; center (also functions as backup), rear, and one in each door handle. When the Start/Stop button is pushed, the BCM activates the antennas, which send out a low frequency signal. If the key is present, it activates, and transmits a high frequency signal to the RTM. The RTM then sends the PATS ID to the BCM over a private bus.

Since the rear antenna is working, that indicates the issue is not with the passive key or the RTM. The door and center antenna do not share connectors or circuits, so it sounds like it may be a BCM or radio frequency interference issue. Are there any aftermarket electronics in the truck, or has anything been wired into the BCM?

The aftermarket electronics I have that I feel could have affected something like this have been in there working just fine for a year. I have:
- Auto start/drop eliminator plugged in behind the monitor.
- Naviks (sp?) plugged in behind the monitor. This is only the one to override using GPS in motion.
- Dashcam battery wired into BCM.

I keep the key in my left pocket so shouldn’t the door antenna work when I’m in the drivers seat? Where is the center antenna? Last week I had replaced my USB wire with a USB-C wire that runs through the center console and up to my Builtright dash mount…if it’s in there I wonder if I accidentally unplugged something?

 

[FordTechOne]

The aftermarket electronics I have that I feel could have affected something like this have been in there working just fine for a year. I have:
- Auto start/drop eliminator plugged in behind the monitor.
- Naviks (sp?) plugged in behind the monitor. This is only the one to override using GPS in motion.
- Dashcam battery wired into BCM.

I keep the key in my left pocket so shouldn’t the door antenna work when I’m in the drivers seat? Where is the center antenna? Last week I had replaced my USB wire with a USB-C wire that runs through the center console and up to my Builtright dash mount…if it’s in there I wonder if I accidentally unplugged something?

Start by eliminating the variables of the aftermarket electronics. They tend to fail over time. I've literally seen EMI from AMP Research running boards take out the EBP sensor on a 6.7.

What fuse did you wire the dash cam into?

Yes, the door handle antenna should have functioned with the key near it in the driver's seat. The center antenna is also the backup; it's located under the center console right next to the cup holder where the backup slot is.

I'd recommend rechecking your work since you just had it apart.

 

[MAMiller44]

Start by eliminating the variables of the aftermarket electronics. They tend to fail over time. I've literally seen EMI from AMP Research running boards take out the EBP sensor on a 6.7.

What fuse did you wire the dash cam into?

Yes, the door handle antenna should have functioned with the key near it in the driver's seat. The center antenna is also the backup; it's located under the center console right next to the cup holder where the backup slot is.

I'd recommend rechecking your work since you just had it apart.

I should’ve noted earlier that I already tried taking out both the auto/stop eliminator and motion override, still had the issue. I know our trucks are weird with anything tapping into the sync system so that was one of the first things I tried. I also tried just resetting sync by disconnecting the negative battery terminal for about 10 mins, no luck there either.

The dash cam battery isn’t off an existing fuse, I used @Specialtyperformanceparts kit that plugs into an extra port on the lowest of the bigger connectors with 1-2 dozen wires. Just tried disconnecting that and no luck. It’s still functioning perfectly so I didn’t blow any fuses there.

Help me out with the antenna functionality real quick? Are the antenna’s in the doors also to track the key fob location when starting the engine, or are those only for access? I just tested with the fob all around the vehicle and being anywhere in the front doesn’t work so if those antennas in the door handles are supposed to allow engine start, somehow I’ve lost both doors and the center console antennas. Any chance you have a diagram showing where the antenna is in the center console? I’ll dig in there tonight and see if something got dislodged there.

 

[FordTechOne]

I should’ve noted earlier that I already tried taking out both the auto/stop eliminator and motion override, still had the issue. I know our trucks are weird with anything tapping into the sync system so that was one of the first things I tried. I also tried just resetting sync by disconnecting the negative battery terminal for about 10 mins, no luck there either.

Sync won't cause a no start, but good idea to start with all aftermarket mods regardless.

The dash cam battery isn’t off an existing fuse, I used @Specialtyperformanceparts kit that plugs into an extra port on the lowest of the bigger connectors with 1-2 dozen wires. Just tried disconnecting that and no luck. It’s still functioning perfectly so I didn’t blow any fuses there.

Can you provide a link? Any unused pins typically won't have power.

Help me out with the antenna functionality real quick? Are the antenna’s in the doors also to track the key fob location when starting the engine, or are those only for access? I just tested with the fob all around the vehicle and being anywhere in the front doesn’t work so if those antennas in the door handles are supposed to allow engine start, somehow I’ve lost both doors and the center console antennas. Any chance you have a diagram showing where the antenna is in the center console? I’ll dig in there tonight and see if something got dislodged there.

Yes, they have dual functionality. So they activate the key when you touch the door handle, or when you press the start/stop button. The signal distance around each antenna is 3ft. The antenna in the center console is shown here, this is the bottom of the center console.

 

[MAMiller44]

Sync won't cause a no start, but good idea to start with all aftermarket mods regardless.

Can you provide a link? Any unused pins typically won't have power.

Yes, they have dual functionality. So they activate the key when you touch the door handle, or when you press the start/stop button. The signal distance around each antenna is 3ft. The antenna in the center console is shown here, this is the bottom of the center console.

Attached picture of the pin used. I’m going to check the center console antenna first thing in the AM. Service appointment is at 7:00. I find it very strange that I seem to lose antenna functionality on all 3 front ones, but somehow retain the rest of the functionality of the door handles. I’ll let you know what I find in the AM.

 

[MAMiller44]

SOLVED! Thanks to @FordTechOne

Not my fault, but the center console antenna was simply unplugged lol. I’ve never actually taken off that lower piece with the cup holders to expose it, only the top trim piece to run a phone charger to the USB port. Turns out the previous owner/dealer had broken the clip on the connector below the cup holders at some point and used a single wrap of cheap quality electrical tape to hold it together. That eventually fell off and the connector just slid out. Seems maybe the antennas in the doors are just some sort of booster and the center console has to be active for them to work?

For others, take this as a warning to do your own research and use resources here even when you’re under warranty! I talked to 3 diff people at my dealer and they were all convinced that an antenna didn’t exist near the third brake light, and that the only antenna was in the steering column. If you read above already, you know this is completely false. Who knows how long they would’ve been chasing this down.