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Alenux
Reduced Key Fob Range

I've noticed that whenever I have the OVMS module plugged into my OBD port, the range on my key fob is significantly reduced to where I need to be standing beside the car to use the fob to do anything. Is this a known issue?

True_Soln
Reduced Key Fob Range

@Alenux at a guess would think its from signal noise then power drain having it plugged in.
Im guessing that its a blue touth or wifi OBD port, and that could be cause noise on frequency that the remote is on.

Janik
Janik's picture
Alenux,

Alenux,

I have the same problem. if you send the wifi mode off command via shell, everything will work as before. but wi-fi will stop work.

markwj
markwj's picture
Is the OVMS module near the

Is the OVMS module near the keyfob antenna? Perhaps try in a different location?

Alenux
Both good points, the OVMS

Both good points, the OVMS must have a frequency band that overlaps. I'll play around with it and see if I can fix it that way. Thanks!

Janik
Janik's picture
Let me know about your

Let me know about your results. thank!

jbeuree
Did you ever find a good

Did you ever find a good location? I tried mounting under the dash just barely on the passenger side, with the antennas run up to the top of the passenger dash. I find not only is the key fob range reduced, but it's sometimes impossible to lock/unlock the doors with the keyless entry and I need to use the buttons on the fob. For some reason the hatch keyless seems to be the worst. If no one has a 'good' location then I may just use a script to completely disable the wifi when the vehicle isn't at home since that's the only wifi it connects to anyway.

Alenux
No updates

Unfortunately I haven't had much time to investigate this further. Been trying to figure out where the keyless entry antenna is located, looks like there's one in the driver side door, one near the rear hatch, then a couple somewhere in the middle of the car, so nowhere near my module. 

I've got my OVMS in about the same place as you, with my GPS antenna at the top passenger window and I'm using the existing cellular antenna in the car (created a custom cable assembly). I'm leaning to towards this being more of a power drain issue since the WiFi/BT module should be operating at a different frequency than the keyless entry fob. But maybe it's polluting the OBD.

philsuth
Ferrite cores apparently efficacious

For what it's worth, I was having a similar problem on my Mitsubishi iMIEV. This afternoon I fitted clip over ferrite cores on each end of the cable linking the OVMS to the OBD2 connector, and the problem seemed to go away. I'll do a little more experimentation in the next few days to confirm what is going on, but this might be a quick fix for others having the problem. It suggests that the OVMS may be generating interference on the frequencies where the keyless entry devices communicate.

jbeuree
That's a great idea. I'll

That's a great idea. I'll look into trying the same thing with the leaf. Where did you order the ferrite core from?

philsuth
I just raided my junk box for

I just raided my junk box for ferrites, as I've used these things before on other projects. I put a larger core (something like this one) at the OVMS module end, and looped the cable through the ferrite twice. I put a smaller one (similar to this) at the ODB2 end and just slotted it directly onto the cable. I'd guess it's the OVMS end core that is actually fixing the problem, but more testing will prove it.

Alenux
More testing

I spent a little time testing today based on philsuth's comment:

  • Adding a ferrite to the OVMS end of the OVMS-OBD cable did not improve key fob performance
  • Adding a ferrite to the OBD end of the OVMS-OBD cable did not improve key fob performance
  • Using the command wifi mode off did not improve the key fob performance
    • Note that this does not power off the wifi module
  • Using the command power wifi off did not improve the key fob performance
    • This command powers down the wifi module
  • Using the command simcom power off drastically improved the key fob performance
  • Unplugging the OVMS entirely drastically improved the key fob performance

According to the FCC ID for the key fob (CWT-WB1U840), the key fob operates at 314.975 MHz. My OVMS module came with the US SIM5360A board (I purchased SKU 9642829,). Is there a way to read back the AT command responses with the simcom cmd [command] command? I'd like to be able to see what frequency band the cellular module is connected to.

As per another thread I created here, I've been using my own custom cable to connect the OVMS module to the existing antenna in my car (the TCU in the car is unplugged). Perhaps while the module transmits there are spurious emissions polluting the key fob frequency range.

For anyone else with this problem, does turning off the SIMCOM module improve key fob range?

achatzii
I have exactly the same issue

I have exactly the same issue, with dramatically reduced range for the fob. In fact, despite having a new battery in the fob, today I was unable to use the fob to lock the car at the grocery store parking lot. Also, I found that disabling CAN write also seems to help with the fob recognition. When I enable it, the key fob stops working entirely. Since CAN write is only used for remote heating and have turned it off for now.

 

 

 

loseby
WiFi mode off helped me

My OVMS finally arrived on Monday and I got it installed. I have had no issues with the proximity features of the key fob, but I did notice that the range of the buttons on the key fob was drastically reduced one day after forgetting to turn wifi off. I did a "wifi mode off" and everything has been good.

I do suspect that device and/or antenna positioning has something to do with it. I used a "4G" antenna from Amazon; it looks identical to the one OVMS sells, which was out of stock. I placed it at the top center of my windshield behind the rearview mirror, and routed the wire into the headliner then down my right A-pillar. I mounted the OVMS on the right side underneath the glovebox. https://www.amazon.com/gp/aw/d/B07GNC8DHH

I intentionally did not install a GPS antenna, and leave WiFi off in an effort to reduce the device's draw on an already temperamental 12v system in the first gen Leaf. Do I read correctly that I should also issue commands "power wifi off" and "power gps off"? My understanding was that the device's power management would switch these off automatically if they are not enabled.

Janik
Janik's picture
I have the same problem.

I have the same problem.

I wrote above that I used the command "wifi mode off", but now it does not help.

What do the developers advise us?

thanks.

Alenux
Simcom power

I have the same problem.

I wrote above that I used the command "wifi mode off", but now it does not help.

What do the developers advise us?

Janik, is the issue resolved when you run the command power simcom off? Note that this will disable the modem, so you'll have to power the cycle the device to turn it back on (assuming you have it set to automatically power up on boot).

Janik
Janik's picture
Alenux, without a modem this

Alenux, without a modem this device does not make sense. do you agree with me?))

Alenux
Agreed, but I'm trying to

Agreed, but I'm trying to find the root cause of the issue so I want to see if anyone else is seeing the same problem.

achatzii
Since I have the same

Since I have the same symptoms, to the point that the key is pretty useless when used as a proximity sensor, I tried turning the SIM off using the command above. I verified SIM was off by looking at the status in the web page. This step did not really help. The only think that helped was to completely unplug the OVMS module from the OBD port....

My OVMS is behind the glovebox, (US model), the GPS antena is below the small window in the passenger side, and the cell antenna is glued on the top of the inside of the windshield (passenger side).

This is tough problem to trace, but I did notice that the proximity response to the key fob degraded rapidly (and) progressively as I locked and unlocked the car 3-4 times, by pushing the oval button on the driver door handle. After 3 times, I could only lock and unlock the car by the fob button, and not the proximity+button on door handle.

And for me too, the trunk is quite worse than the driver door.

 

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