An actual car question - iffy remote

Kinja'd!!! "RiceRocketeer Extraordinaire" (ricerocketeer2)
10/05/2020 at 20:34 • Filed to: None

Kinja'd!!!0 Kinja'd!!! 7

I have two OEM Honda remotes for my car - one works reliably, the other not so much. Maybe 1 in 50 button presses actually results in something happening (lock/unlock/trunk), so it’s not completely dead and it’s still programmed to my car. I’ve tried re-re-re programming it and changing the battery to no avail. Thoughts?

Kinja'd!!!

DISCUSSION (7)


Kinja'd!!! Roadkilled > RiceRocketeer Extraordinaire
10/05/2020 at 21:07

Kinja'd!!!3

Disassemble the fob and look at the back side of the rubber button. There is normally a carbon or graphite disk. When pressed, the disk shorts between two exposed terminals on a circuit board. That carbon disk can wear away over time.

I fixed one remote, at least temporarily, by gluing a circle of alumin um foil to the back of the rubber button where the carbon disk used to be.


Kinja'd!!! Jb boin > RiceRocketeer Extraordinaire
10/05/2020 at 21:09

Kinja'd!!!0

If it’s like on VW cars, you can buy another used remote (or one on Aliexpress if available for your model ) and program it to work with the car and it will not cost more than a few bucks.


Kinja'd!!! Deal Killer - Powered by Focus > RiceRocketeer Extraordinaire
10/05/2020 at 21:25

Kinja'd!!!2

Most auto parts stores sell replacement fobs. I know auto-zone have them. I replaced my wife’s Explorer fob for a new one. Worked fine.  


Kinja'd!!! RiceRocketeer Extraordinaire > Roadkilled
10/05/2020 at 22:46

Kinja'd!!!0

Forgot to mention - a red LED lights up when I press the button, so the keypress is registering at least. Could be that the transmitting part of the remote is toast though ...


Kinja'd!!! Roadkilled > RiceRocketeer Extraordinaire
10/05/2020 at 23:34

Kinja'd!!!0

Here is my next thought. Open it up and look at the circuit board. There is an antenna on that board somewhere. It’s probably a long trace (monopole antenna) or two traces going opp osite directions (dipole antenna.) If there is a corroded trace, it could be a broken antenna. If so, you may be able to solder a wire in to replace it or to bridge the open gap with solder.

In North America, the fobs are usually working at 315 MHz. Even a 1/4 wavelength antenna is far too large to fit in a fob. Whatever the antenna they have in there is pretty inefficient to begin with. It wouldn’t take much damage to make it worse.


Kinja'd!!! RiceRocketeer Extraordinaire > Roadkilled
10/05/2020 at 23:53

Kinja'd!!!0

Took it apart for grins and giggles. Anything stand out to you?

edit: it seems to work reliably now after reassembly. wtf ...

Kinja'd!!!

Kinja'd!!!


Kinja'd!!! Roadkilled > RiceRocketeer Extraordinaire
10/06/2020 at 09:42

Kinja'd!!!0

I don’t see any broken or cold solder joints. My next guess is still in regards to the antenna. There is an antenna terminal on the back side of the PCB. Does that metal bar touch anything in the plastic case? If there is an antenna built into the case, it might have been that the PCB’s antenna terminal wasn’t making good contact with the actual antenna. Opening and closing the case could have reestablished that connection.