Remote Start

[Nate4x4]

This is a testament to how valuable forums can be. And also why the Longhorn is awesome.

I had NO idea. I always push my door handle button. I had no idea it was there!

I am so glad this thread was started. Thank you SO much.

This is the best news of my day today. Not sure what can top this.

Well this made my day...

 

[Longhorn5G]

Oh okay, if it doesnt STAY lit after I lock it, then this isnt that great of news after all. I will check later.

**update** it does not stay on. Back to square one.

 

[Jordan2929]

It's most likely its just a battery indicator. As long as the light flashes with a button click then the fob is working, if it doesn't flash then you need a new battery and its not something wrong with the truck.

 

[Nails]

^^^ would love to see some more fancy to it. Agree with above seems still just a indicator that it’s alive or has pushed a message.

 

[SpeedyV]

Well, according to @Nate4x4's earlier post, it's a "2-way fob". The mystery continues...

 

[Longhorn5G]

I' pretty sure when the battery is dead or low, the truck will tell me on the dash info screen. In fact, it wont just tell me. It will PESTER me until I change the fobs battery. @Electrical probably knows what I am saying. Hes probably been hounded by his durango, the same was my jeep hounds me about it.

 

[Electrical]

The keyfob and TPMS work similarly. Both are required to operate in the ISM band. 325 MHz in North America, 434 MHz in Japan, Europe, and a few others.

Believe it or not, there is absolutely no standardization for how OEM's implement these systems apart from a few FCC regulations for interference.

That is to say, OEM's are free to design-in as many or as few features as they want. The key is balancing battery life: more features = more power = less life.

You want TPMS that transmits tire location, temperature as well as pressure, and you want it to update every 2 seconds and never go to sleep?

Ok... we'll just need people to replace them every 2 years. Not good.

Solution? Expand the update interval, eliminate temperature measurement, allow them to sleep when parked and there's a TPMS sensor that'll run for 10 years.

Fewer features = longer life.

Apply that reasoning to the keyfob and ask yourself how many features you REALLY want.

If they can design this thing so I never have to change the battery, I'd take that every day over an LED indicator.

 

[Brent T]

FOB is not 2 way. Few friends with them.
My truck the command start won’t even work unless you are 20 ft from truck ? And ideas ? Uconnect app also will not work to start truck.

 

[MJP]

FOB is not 2 way. Few friends with them.
My truck the command start won’t even work unless you are 20 ft from truck ? And ideas ? Uconnect app also will not work to start truck.

Uconnect app is a common issue. Call the Uconnect people to get it on record so FCA comes up with a fix for everyone. I had my dealer check into it but they didn't know what to do and didn't want to start swapping parts prematurely. Mine only works after the truck has been started and only for about an hour then it goes into some sort of sleep mode. The more people complain to FCA the more likely a fix will come. Meanwhile we dont get to take advantage of the free trial period which pisses me off but it is what it is.

 

[SpeedyV]

Apply that reasoning to the keyfob and ask yourself how many features you REALLY want.

If they can design this thing so I never have to change the battery, I'd take that every day over an LED indicator.

Before the "Keyless Enter-N-Go" features, some keyfobs used to recharge while plugged into the key slot in the column or dash. The (tiny) price we pay for the convenience of keeping our keys in our pockets...

 

[Old Ray]

My 2018 "other make" daily driver has confirmation fob green led of start. (two way)

(So one more small cut to FCA on my score card) Oh,........... and yes that IS my fault.

 

[Neurobit]

The keyfob and TPMS work similarly. Both are required to operate in the ISM band. 325 MHz in North America, 434 MHz in Japan, Europe, and a few others.

Believe it or not, there is absolutely no standardization for how OEM's implement these systems apart from a few FCC regulations for interference.

That is to say, OEM's are free to design-in as many or as few features as they want. The key is balancing battery life: more features = more power = less life.

You want TPMS that transmits tire location, temperature as well as pressure, and you want it to update every 2 seconds and never go to sleep?

Ok... we'll just need people to replace them every 2 years. Not good.

Solution? Expand the update interval, eliminate temperature measurement, allow them to sleep when parked and there's a TPMS sensor that'll run for 10 years.

Fewer features = longer life.

Apply that reasoning to the keyfob and ask yourself how many features you REALLY want.

If they can design this thing so I never have to change the battery, I'd take that every day over an LED indicator.

Our RAMs operate on low freq for both lock/unlock operations as well as TPMS. 125 kilohertz to be exact.
Unfortunately, no description anywhere on how the LEDs operate on the FOB.

Cheers,

 

[Electrical]

Our RAMs operate on low freq for both lock/unlock operations as well as TPMS. 125 kilohertz to be exact.
Unfortunately, no description anywhere on how the LEDs operate on the FOB.

Cheers,

Good stuff NB! Thanks for posting that; very cool. Can you post the TPMS info?

 

[Neurobit]

Good stuff NB! Thanks for posting that; very cool. Can you post the TPMS info?

Here you go. Looks like TPMS does work on a diff frequency (433 MHz).

Cheers,

 

[Electrical]

I think some interpretation is needed when reading the key fob sheet. The TPMS sheet explicitly says 433 MHz, but unless the world is upside down I can promise you the key fob long-range function also operates on 433 MHz. If FCA (or any OEM) cranked up the power of the 125 kHz signal to transmit "long range" they'd be in violation of FCC... and also of the analogous regulatory bodies overseas. There is no leeway here. The allotted frequencies are written in stone.

The RFH uses low-frequency to communicate with key fob in-cab and near-cab but long range is different. One of the stated inputs of the RFH is "Remote start antenna's RF signal". So... even though not mentioned in great lengths, an RF antenna does exist, it's connected to the RFH, and it's used to capture commands from the key fob. Even though only remote start is mentioned, the same needs to be true for the other key fob commands: door lock, tailgate, E/E mode, panic, etc.

Antenna's are inherently two-way; if it can transmit, it can receive. What prevents two-way operation is the IC; the chip in the key fob. It takes money, space, and battery power to add the demodulation circuitry needed to capture an over-the-air signal and convert it to digital. There are no regulations preventing FCA from making it two-way but when dealing with compact battery powered devices, the usability and feature tradeoffs become a serious discussion within development groups.

Battery life is stated to be approximately 3 years. Making a two-way key fob could potentially reduce life to 2 years or less. I'd rather have the longer life. The key fob RF is one-way and the LED only blinks when the key fob is transmitting RF. There is also no stated RF output from the RFH. LF, on the other hand, is obviously two-way.

 

[Brent T]

Ford trucks fob is the same size as ram, maybe a touch smaller and has two way. Light flashed green back at you when truck has started. So it obviously can be done with out much problem.

Anyone know of a good aftermarket one we could add on to these rams that are 2 way?

 

[Electrical]

In my mind it's not a question of "can". It's a question of "want". There's lots that can be done but only so many mAh in a coin cell battery; how do you want to use them.

 

[Brent T]

I want to know my truck actually started when I hit the button. Will gladly buy a new battery every year for fob.

 

[Electrical]

If enough people share that opinion maybe Ram can be persuaded. Would be interesting to see a poll.

 

[Chris]

Antenna's are inherently two-way; if it can transmit, it can receive. What prevents two-way operation is the IC; the chip in the key fob. It takes money, space, and battery power to add the demodulation circuitry needed to capture an over-the-air signal and convert it to digital. There are no regulations preventing FCA from making it two-way but when dealing with compact battery powered devices, the usability and feature tradeoffs become a serious discussion within development groups.

I’m not an RF engineer, so my understanding may be limited; however, I was under the impression that a small antenna outputting a weak signal (key fob) can be received by a large antenna (vehicle) but that same signal cannot be broadcast from the large antenna and recurved by the small one unless the strength is boosted (which the fcc prevents) or the small antenna is increased in size.

Obviously, this can be done at a small size since many other manufacturers and aftermarket remote starters are 2-way; I don’t know what the size of the current antenna is in the fob, but based on needing a second antenna for low frequency and all the extra electronics there may not be enough space for a high frequency antenna large enough to receive the FCC restricted signal strength from the truck at long range.