I have a 2017 cvo limited with pressure sensors in tires. Recently installed a Jims force flow fan 5468. After installing I was getting code about my sensors while the fan was running, when I manually turned the fan off the sensors reset and were transmitting pressure reading. It seems as though the fan is interfering with the frequency these sensors are using. Any one know about a noise filter that can reduce the frequency noise??

 

very true, they work off RF signal. they can go bonkers also when you pass someone running big tennis shoes on their cb radio.
you might try shielding on the fan wiring or re-route them as distance can make the diff. another trick is to add a filter capacitor on the fan to shunt the rf to ground.

 

Jims said they never heard that problem an wanted to argue with me. Put a filter on fan a rerouted wires and guess what, problem disappeared.

 

Glad you found a cure!!

 

I take it was an electrical filter. Ferrite beads? Simply a Capacitor? Both?

 

Great information to have in the memory bank.
Thanks for posting!

 

the beads are usually used in the power end of the circuit where frequency is low but as frequency increases, the beads actually hurt the circuit. often times a capacitor is used with one to help filter out noise when the bead cannot forming a low pass circuit. when you talk about rf frequency and the tpms frequency is pretty high, the beads are not very useful. the issue is not in the power end but in the fan, the way it was designed. i do not know what type of motor is used but a lot of newer motors are electronically driven using switching circuits which make the motor super power stingy and adds more torque as the power is controlled and not free flowing which on a battery operated devise increases life or usefulness of the battery. these switching circuits could be the source of the emf and if near enough to another circuit, could be induced into it. computers are stupid and if you confuse it by altering the data, go bonkers. you can blind a satellite dish with a 1/4 watt transmitter placed near it knowing base band frequency and adding 1 khz modulating tone which rides in on the data stream corrupting the data and the system goes bonkers.

 

I don't understand. Beads would block high frequency from the fans so they power leads don't interfere with the tire pressure RF. Don't know if the fans are bushed or brushless but I suspect either could generate EMI.

 

the beads are one of the most misunderstood passive component. they operate1. in inductive mode, 2. resistive mode and 3. capacitive mode. each has certain characteristics.
very low frequency the inductive part tries to keep the current constant as it resists changes, next up, it operates in a higher frequency range as resistive which is its best mode and dissipates the emf into heat and further up the frequency range it goes capacitive mode which can become parasitic.
what is bad is there is a slopping peak for each region and occurs at cross-over frequency and the steep downward slope afterward which makes a negative impact on its filtering capacity in that mode.
tpms are in the UHF band 315 mhz and 433 mhz which are basically outside the range for effective control.
but i do not think that is the problem as the fan emf could not be that high to corrupt the rf data flow. that leaves the fan power leads acting like antennas introducing emf in near by circuits especially if running in parallel, the same can happen with plug wires.
so adding a bead with/without a capacitor should be of help.