knovak17

I had a remote start installed and they are telling me that there is something wrong with my vehicle because the vehicle will not start if they remove the battery from the key fob and hold the remote up to the start stop button. I called my dealer and they told me if they remove the battery the vehicle will not start. I am wondering if anyone has tried this or if someone would try this and get back to me?

Brown13

Don't have to try this.Fob sends a signal to the ECM to enable start function.No battery,no signal,no start.

RDX-Rick

Interesting question. The manual says the procedure will only work if the battery is weak. My theory is that the transmitter needs at least 3 volts to operate, as the voltage drops to less than 3 volts (which took over 2 years for me), you will start to get low battery warnings which give you maybe a week's warning before it stops altogether.

As the battery voltage drops further, the key will no longer start the engine unless it is held close to the START button.

Perhaps the antenna that receives the signal is located near the start button and the weak signal is picked up better in this location, if this is the case, then it would not work without a battery installed.

Another possibility (and the most likely) is that a coil located around the button creates an induced voltage inside the fob (the same way a Qi Charger works for a smart phone) which provides the power to make the transmitter work again. The thing is I don't think the coil could provide enough power to operate the FOB, I think it just supplements a weak battery. If I am correct, then the FOB would not work without a battery that just failed recently.

Since your system works normally when the battery is installed, I think your system is normal, and not starting without a battery is also normal.

Hopefully someone has time to perform the experiment.