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Why aren't you using a ferrite core to suppress the EMI, sounds to me like that is whats causing the issue, I see the idea of a cap but I'll leave that one alone.
All LEDs create some degree of EMI, even if negligible - I work for Boeing and there are certs (DoC) we need for certain types of designs as they can cause interference with comm equipment in the MHz range.
Its probably the LED type used that is causing excessive noise or spikes in noise that are interfering with the TPMS signals. I have the LED sidemarkers on my C6Z but never heard or seen issues of those in the C6, again maybe the LED type used or overall design doesn't have RFI/EMI suppression accounted for. Here is an example of noise generated by LEDs:
The OEM TPMS appear to work at 433mHZ so the following should work (and they are clip on) - There are many other ways to solve this including soldering ferrite beads but I think you guys get the idea
Sorry guys I dont have a C7 otherwise I'd be out mucking with it to see what I find out instead of posting
Although my LED side markers are not interfering with the TPMS I like the idea of installing the Ferrite Clamp On Cores as a proactive measure. My question is where on the side marker wiring are they clamped? Do I need one core for each wire or simply clamp one ferrite core over the wires near the connector?
If the interference is coming from the lights via the wiring, then get the chokes right at the source. Put them on the wires where you can first attach them from the lights. I'd open the corners up again and put the chokes right at the lights on the wires.
Mine are installed as Elmer indicated, immediately behind the connector as close to the lamp as possible. The left rear wiring loom was longer than on the others on my car so I used one of the larger chokes that fit over the loom but was close to the connector. The smallest ones fit over the exposed wires on the other three lamps.
I can confirm that all 4 chokes WORK, the TPMS continues updating... I have driven the same exact route where the front TPMS would not update and would give the error twice with lights on the whole drive... All TPMS updated during the entire drive and stayed exactly the same pressure reading once I slowed down and stopped...
I took the wify out last night and ran again 40 min hwy drive and still nothing cut out.
It seems to hit the new and old model years. Maybe a LT difference? Mines a 1LT? anyone else with that having the issue. Maybe twist the crap out of the wires like cat5. lol who knows...
Unfortunately, the chokes did not work for me. I added them to the other three markers this morning. The wiring looms were very close on 3 of the 4, so I could only use the larger size on those. I took it out to test it and there was no change. I still received the TMPS error system message after a few minutes of freeway driving. It does go back to normal once the lights are off. I wish it had worked, I liked the lights very much.
I ordered some from JW as well, they look super nice but I guess I’ll hold off on the install for now. Great thread, hopefully we can find a solution. What are you guys doing to clear the tps codes? I had something called a blue driver I used on my last car to clear codes.
Last edited by MorrisZ51; Jun 16, 2020 at 02:51 PM.
Unfortunately, the chokes did not work for me. I added them to the other three markers this morning. The wiring looms were very close on 3 of the 4, so I could only use the larger size on those. I took it out to test it and there was no change. I still received the TMPS error system message after a few minutes of freeway driving. It does go back to normal once the lights are off. I wish it had worked, I liked the lights very much.
Oh snap... This is bad news. I thought this problem was conquered. Is there a chance that your batteries are weak in the TPMS for the '14?. They are 6 years old. I wonder how long the batteries last in the TPMS? Found out the battery question, battery life averages 5 to 12 years depending on various conditions.
Elmer
Last edited by eboggs_jkvl; Jun 16, 2020 at 03:26 PM.
Turning the lights of clears the problem and turns off the TPMS light. The code will be in history, but not current. I would not be concerned with clearing the code from history.
Unfortunately, the chokes did not work for me. I added them to the other three markers this morning. The wiring looms were very close on 3 of the 4, so I could only use the larger size on those. I took it out to test it and there was no change. I still received the TMPS error system message after a few minutes of freeway driving. It does go back to normal once the lights are off. I wish it had worked, I liked the lights very much.
I just went out to the garage to install my set. I see that the wire loom does go almost to the connector. With regards to the chokes, does it make any difference if it goes around the loom or directly over the wire? Seems that it would be easy to trim the loom back enough to get the choke around the wire.
Release the looms as a test and then use the smallest choke down on the wires. Leave everything loose and test. I don't see it hurting anything to be loose for a few minutes drive to test the chokes around the wires rather that around the loom covering the wires.
Oh snap... This is bad news. I thought this problem was conquered. Is there a chance that your batteries are weak in the TPMS for the '14?. They are 6 years old. I wonder how long the batteries last in the TPMS? Found out the battery question, battery life averages 5 to 12 years depending on various conditions.
Elmer
It is definitely possible that the batteries in the sensors are weak. They seemed to be working fine though and no problems before. I have a 2008 Silverado that is just now starting to need replacement tire pressure sensors (1) with 100,000 miles on it. At this point, I can't justify going to that expense. I will give it a few days as they aren't causing me a problem right now in case I hear I did something incorrectly. Jhonathan has been great to work with so far and knows I would prefer a solution to returning them if possible.
I ordered some from JW as well, they look super nice but I guess I’ll hold off on the install for now. Great thread, hopefully we can find a solution. What are you guys doing to clear the tps codes? I had something called a blue driver I used on my last car to clear codes.
why would you hold off? Its not that hard to put on or take off and there may be only a 5-10% chance of you even having the issue. Pop those bad boys on.
Last edited by lostsoul; Jun 17, 2020 at 01:06 AM.
why would you hold off? Its not that hard to put on or take off and there may be only a 5-10% chance of you even having the issue. Pop those bad boys on.
just until I order the chokes, don’t want to take a chance and do it twice
First, if the problem is worse on 2019s (and 2018s) please keep in mind that GM changed the TPMS on those years. 2014 to 2017 are the same system. 2018 and 2019 is a new system that may be more susceptible to the EMI generated by the LED voltage regulator.
Second, when using the ferrite filters, the smaller the inside diameter of the filter (making it closer to the wires), the better it will couple to the signals in the wires and the more effective it will be.
Third, if your TPMS sensors have low batteries, the signal they send out will be less powerful thus more easily interrupted by EMI from the LED regulators.
Forth comment, if you are going to use foil tape to shield the wires, the tape needs to be connected to vehicle ground. An ungrounded foil shield is not providing much of a shield at all.
Fifth comment, someone mentioned twisting the wires. If that is possible it is a great way to cancel out common mode high frequency noise, so it might be effective in this situation.
Last comment, someone asked if you can put the ferrite beads on each individual wire. If they meant each conductor, then no. The ferrite bead couples to the high frequency signal in the wires. By coupling to both wires in the circuit, one wire is carrying forward current and the other wire is carrying the reverse of that current. The bead works by coupling to both signals and allowing them to cancel each other out. Having the bead around a single conductor will do nothing.
I hope you guys get this fixed. I may one day buy some of these side markers for my car, so it will be nice not to have to do a bunch of experimentation to fix a known problem.
