Key Fob distance

[Docron]

Everyone's experience will be different. RF is very peculiar on how it behaves. There are many variables, specially obstacles and interference from other sources, With clear line of sight, I can easily get 200-300 ft or more.

For the nerds...

There are five Low Frequency (LF) antennas located on these vehicles. These LF antennas allow the key fob within the RFH (Radio Frequency Hub) to communicate with a key fob that is located inside the vehicle or, at most, about 1.5 meters (5 feet) from the door handle touch point.

The LF antennas are located:

1. rear left door
2. rear right door
3. rear cab back
4. center console
5. rear bed/bumper

The RFH uses communication through the LF antennas to wake up and challenge a key fob that is within range in order to authenticate whether that key fob is valid (programmed) to the vehicle.

The RFH communication with the key fob is on a 125 kilohertz using Amplitude-Shift Keying (ASK).

Each antenna unit has two dedicated connections to the RFH. One connection is the LF antenna output circuit, while the other connection Is the LF antenna return circuit. These circuits to each antenna unit are a twisted pair to help reduce the potential for induced electrical interference. The RFH continuously monitors all of the LF antenna units and will store a DTC for any fault that it detects.

very interesting information, thanks!

I recently installed an OPT7 LED lightbar with the Curt trailer wiring harness splitter.

And my push button start capability to keyfob distance is now only about 12 inch detection and dash messaging warns me if my key fob is more than 3 feet away. i have always kept my keyfob in my workbag that i typically place on the passenger seat with no problems.

how is the LED lightbar and/or Curt trailer wiring harness splitter affecting these antenna and keyfob communication? Thanks!

 

[Neurobit]

very interesting information, thanks!

I recently installed an OPT7 LED lightbar with the Curt trailer wiring harness splitter.

And my push button start capability to keyfob distance is now only about 12 inch detection and dash messaging warns me if my key fob is more than 3 feet away. i have always kept my keyfob in my workbag that i typically place on the passenger seat with no problems.

how is the LED lightbar and/or Curt trailer wiring harness splitter affecting these antenna and keyfob communication? Thanks!

The main culprits are cheap LED brake light replacements (ones located in the cargo light housing above rear window). The theory is that since you have to press the brake pedal to start the truck, it energizes the bulbs and causes the interference.

I did have this issue with el-cheapo Chinese lights from Amazon when I should have known better. I replaced them with Diode Dynamics LEDs and problem went away immediately.

Cheers,