Scrutator

I put on my winter tires about three weeks (2013 F Sport) ago for my frequent trips to the snowy San Bernardino Mountains here in Southern California. I had cloned my four regular tires with my TPMS codes so I wouldn't have to screw around with reprogramming when I switched out. I didn't clone the spare and left it untouched.

So I switched out the tires and was good for the two days before I made the trip up the mountain. Then, about forty miles into my trip the TPMS warning light came on and no pressure readings showed on the display. Not even the spare showed up. So I figured I'd screwed up the programming somehow and that the car finally caught up with it. Drove around for two weeks with no TPMS readings at all.

So last week, while still wearing the winter (cloned) tires, the readings showed back up, except for the spare. Then, with another week of driving, the spare finally showed up on the display; then it went away. So now, sometimes the spare shows up; sometimes it doesn't. Keep in mind that I haven't touched the car's programming at all; only switched out four tires. The four winter tires are consistently showing up now, but the spare is hit or miss. I went to my regular mechanic and he had nothing to say other than that he deals with TPMS issues regularly and that they're frequently not readily resolved.

I can live with this during the winter months but I'd rather have it working, especially considering the time, effort, and expense I went through to ensure that it works.

Any ideas?

superdenso

A set of Denso tpms are $120 and the program tool is $150 (all from AMAZON). The ordeal should cost less than $500 including replacing your clones at a tire shop. Yeah, reprogramming at every swap takes 4min.; less when you get good at it. But when it's done there are no glitches

jmcraney

I think with a better understanding of how the TPMS works you will be able to sort this out.

The first thing you need to consider is that the TPMS must go 20 minutes for a non-reporting sensor to cause a problem. If you are driving pretty fast that represents about 40 miles.

When you clone sensors and have both sensors collocated near the location where you start your car, either or both sensors can be reporting to the car, if the sensor ID is registered in the car, until the car moves out of range and then it's just the sensor that is on the car that is reporting. What happened in your case is that before you left your start location all 5 registered sensors were reporting. But as soon as you moved out of range there was only 4 sensors reporting and 20 minutes after your car failed to receive reports from 5 sensors it went into a fault condition. Bottom line is you don't have all the IDs for the sensors on your car registered in the car.

The other thing you need to pay attention to is whether you car displays the locations correctly. I am not sure the '13s display locations but I believe they do. For cars with the localization feature you need to remember that localization occurs during benchmarking, so any tire position changes, such as rotation or swaps with the spare, after that are not tracked.

One way to get an understanding about what is happening is to drive your car away from where your other tires are stored, a couple of blocks is probably far enough, and turn the ignition off and then restart the car. On the pressure display the reporting sensors will be represented by some pressure number and the non-reporting sensors will be represented by dashes or "checking" - you may need to allow a couple of minutes for this to settle. Keep in mind that positions may not be correct and you will not be able to benchmark until you get all 5 sensors reporting.

This is a little hard to understand. If you have any questions don't hesitate to ask.

The TPMS is very reliable but without an understanding of what is going on it seems a little mysterious. I don't think most mechanics and a lot of tire professionals understand this system.

Scrutator

I appreciate the time and detailed response. But I've driven the car all around town, starting it up miles from my other tires. The winters are showing fine for now but the spare, which I never cloned, appears then disappears. Just to be certain I'll move my four summer tires farther away.

jmcraney

I'm sorry that didn't help - I am at a disadvantage without more information.

Let me try you on a couple of examples.

Let's say the sensor-cloning is not the issue and there are no duplicate sensor IDs to be concerned about. I will use a couple of scenarios to describe how the TPMS works.

In the first case let's say that all 5 tires are inflated to 33 PSI, you are at home and the car is parked in the garage and you take the spare out and lean it against the garage wall. Then you start the car and after a minute of so you see that 5 pressure reading are showing in the dash display. You drive away to a destination that is 15 minutes away. In route you observe that there are 5 pressures displayed and you park after you have driven 15 minutes and before you turn the ignition off you observe that there are 5 pressures displayed. Four of the displayed pressures are likely from sensor reports less than a minute old and one of the pressures is from the spare that was taken 15 minutes earlier. The rule here is that the display shows the LAST reported pressure from each sensor.

A few minutes later you come back and start the car and after waiting a minute or so you see that 4 pressures are displayed and the other sensor display position shows dashes or "checking" and en route home, a trip that takes 15 minutes or less, you observe that one of the pressure displays remains blank. When you get home the blank display suddenly changes to 33 PSI because you are now in range of the spare sensor getting reports from 5 sensors.

The next day you take another trip, leaving the spare behind, but this time the trip takes 25 minutes. The first 20 minutes of this trip would be like the previous days trip - 5 pressures displayed. At the 20 minute mark the TPMS would go into failure alarm and remain in that state until you turn the ignition off. When you start the car again you would have 4 pressures displayed and one would be blank, like the previous day. If the trip home takes more than 20 minutes it would go into failure alarm. The rule here is if any sensor goes longer than 20 minutes without reporting then the TPMS will go into failure alarm.

You need to keep in mind the information that I gave you about localization. That may or may not be important to you.

Scrutator

Got it. All makes sense; however the spare remains untouched in the trunk.

Scrutator

Okay, the weirdness continues. I moved my summer tires--except for the spare that remains in the trunk--to the back of the house. I'm confident that there's no "communication" with the car from those tires. Now I get nothing on the display. Nothing.

So, it seems that the initial communication that took place between my summer tires that were in the garage, said "Hey, I'm here!" with the car, then maintained communication with my cloned winter tires for some time. It's apparent that the winters were communicating for quite some time because the pressures would change as I drove for miles and miles as the tires heated and cooled. Then, after a 25-minute trip to the movies and another 25 minutes to another location the tire pressures then went blank and have not returned.

So, in effect, it appears that the initial communication with my summers makes the cloned winters show for a while (except for the uncloned, unchanged spare). Then it decides that it can't communicate any longer and drops everything. So, I'm going to try my ATEQ QuickSet TMPS reset tool and tweak the programming on the car and see if I can get them to show. When I cloned the winter TPMSs I had to drop the "zero" in the front while coding. Maybe that make a difference.

jmcraney

The wheel sensors are radio frequency transmitters and anything that interferes with those signals would cause a problem like you are experiencing. You may be experiencing a Radio Frequency Interference problem. RFI can come from electrical appliances, fluorescent/sodium vapor lights, arcing electrical power lines, radio and television transmitters, cell phone sites etc. Just changing the location of the car gets you out of some problems. RFI can come from devices that are in your car and some possible sources would be radar receivers, personal communications devices, charging devices or some sort of tracking device.

Scrutator

I doubt that this is RFI. I used to be a licensed amateur radio operator. I remember 35 years ago when I went through my entire condo complex installing capacitors on everyone's oven control boards because they were emitting spurious RF and screwing up the lower VHF TV channels. I doubt that this is the issue here.

jmcraney

If you'll google "TPMS RFI" you will see that it is a common problem.

Scrutator

Will do. Thanks.

In the meantime, I tried another experiment. After moving my four summers to the back of the house and getting no display from my winters for two days, I moved two of my summers back next to the car. Then I started it up and waited. So what happened? Four tires now show on the dash.

I went for a five-mile drive to the store and back and the winters are obviously showing because the pressures changed slightly as I drove.

Fun stuff.

jmcraney

Sort of reminds me of my garage door opener problem of a few years ago.

The garage door opener/closer in my car had been working flawlessly for a couple of years.

I came out one morning, got in my car, backed out and hit the garage door button in my car to close the door. The door would not respond. I finally had to get out of my car and push the manual button inside the garage and exit through the front door.

When I returned in the evening, I tried the button in the car and the door responded immediately. I closed the garage door with the manual button and went into the house.

Next morning, same thing, door would not respond to commands from the car. When I returned in the evening, same thing, door worked fine. This went on for several days,

Then a few days later I discovered that I could open and close the garage door from the outside as long as I kept the car outside. That was really confusing.

After giving it some careful consideration, I figured out that my florescent light inside the garage that came on because of a motion sensor had a significant flicker. When I replaced that fluorescent tube the problem with the garage door opener went away and never came back.

I believe that the garage door openers and TPMS operate on nearly the same frequencies. Some defective devices generate broadband RF noise that will interfere with collocated electronics like bluetooth, TPMS, WIFI, wireless car keys etc. Fluorescent and sodium vapor lighting are common offenders.

jmcraney

You need to also consider that your "cloned sensors" are the wrong part# and will not support your car. Some TPMSs use sensors that are activated by motion and others are activated by an interrogation command from the car. Nearly all sensors go to sleep when they are still for a while, as a battery preservation action.

Mekoz

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