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Discussion Starter #1
I just put the full size spare tire on my car and drove on it for about 20 miles and didn't get any message or light from the TPMS system. The spare does not have a TPMS sensor in it. The owner's manual states the TPMS light should flash while the spare is in use.

Has anyone had a message from the TPMS system for low tire pressure, using winter rims without sensors or when using the spare?

Add this to the list of things that don't operate correctly on this car.
 

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Why did you have the spare on? Was the original tire (with sensor) being hauled around in the car? What was the condition of it?
 

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Discussion Starter #3
I was testing the operation of the system to decide if I want to buy TPMS sensors with my winter tire package or not.

The original tire and rim was sitting in the garage at home.

I have the full size spare tire with the handling package.
 

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Discussion Starter #5
I don't think so, they have never done this in the past and the owner's manual doesn't indicate as such. The rim is a steelie and it is marked as temporary. The stem is also standard, you can tell the ones with TPMS by a longer section of metal between the stem's rubber portion and threads.
 

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the FSS is a steelie? I thought it was just a 5th wheel the same as the others... atleast I saw a picture of it in the trunk like that.. maybe im wrong
 

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I just put the full size spare tire on my car and drove on it for about 20 miles and didn't get any message or light from the TPMS system. The spare does not have a TPMS sensor in it. The owner's manual states the TPMS light should flash while the spare is in use.

Has anyone had a message from the TPMS system for low tire pressure, using winter rims without sensors or when using the spare?

Add this to the list of things that don't operate correctly on this car.
Try this thread

http://www.focusfanatics.com/forum/showthread.php?t=270739

I did mine on saturday it finally triggered on monday and wouldn't stop until I reset them. Appears to be time as opposed to mileage as my mileage was over 100 miles before engine noticed that I didn't have original sensors connected.
 

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The full size spare is not the same wheel you have on car. It is just a bigger spare. (seems a rip off to me.. but I have a small spare.. just because it was what was on the car I bought. (not ordered, bought 60 miles away to find right stuff)
The TPMS is such an odd thing.
 

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To Test the TPMS
Make sure you have a compressor with you to re-inflate the tyre.
Deflate one tyre (say to 15 PSI).
Drive slowly, TPMS should pick it up immediately. That's what it's for.
It needs to communicate with the sensor to read the pressure.
 

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Discussion Starter #11
Not all TPMS systems have the long metal section in the valvestem.
Maybe, but in answering another poster's question about the spare having a TPMS sensor, the stem was different on the spare, thus doesn't have a TPMS sensor.
 

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To Test the TPMS
Make sure you have a compressor with you to re-inflate the tyre.
Deflate one tyre (say to 15 PSI).
Drive slowly, TPMS should pick it up immediately. That's what it's for.
It needs to communicate with the sensor to read the pressure.
Is it possible that the car just kept trying to read the sensor and since it wasn't present, kept trying again and again and then eventually timed out and displayed the message on the screen?
 

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Discussion Starter #13
It needs to communicate with the sensor to read the pressure.
This is not true according to the owner's manual (or "bible" as you call it).

With one of the sensors not present or faulted, it should give you a message and light that something is wrong. That's the whole point of the TPMS system.

Also note, when you post information which may be true on your car (since you live in South Africa) it may not be the same on US or Canadian Focus.
 

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Discussion Starter #14
Is it possible that the car just kept trying to read the sensor and since it wasn't present, kept trying again and again and then eventually timed out and displayed the message on the screen?
This is what should be happening, but it isn't.
 

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From what I have been informed is that when a tire with a TPMS sensor is removed and replaced with a spare that does not have a TPMS sensor it can take several day for the computer to run it's random check on all the tires to check that the TPMS sensors in them are operating properly.

In comparison to a tire with a registered TPMS sensor, senses an air loss below the 25% set mark, it instantly triggers a fault code to the computer to inform the computer of the loss of air.

In your case you removed one of the tires with a TPMS sensor and replaced it with the factory spare which does not have a TPMS sensor, and as of yet the system has not shown a fault code for the spare.

As long as the original tire is not in the car or garage where the original TPMS equipped tire is being stored it will show a fault within 3-4 days.

Apparently the reason for this is that the batteries on the TPMS sensor have to be rated for a minim of 5 years and that they only check in with the computer every 3-4 days otherwise they would go dead from overuse if they say were checking in every hour or so.

The sensor in the tire will however report immediately an air loss of plus or minus 25% air pressure to what it was set to
 

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If you still have the original tire and wheel in the trunk of the car and it has the correct amount of air pressure in it, then your car will not notice a low tire.
 

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If you still have the original tire and wheel in the trunk of the car and it has the correct amount of air pressure in it, then your car will not notice a low tire.
Oh, because it's still in range? Awesome!
 

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Discussion Starter #18
If you still have the original tire and wheel in the trunk of the car and it has the correct amount of air pressure in it, then your car will not notice a low tire.
Did you read the whole thread?

Here, post #3: The original tire and rim was sitting in the garage at home.
 

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Discussion Starter #19
OK, since I didn't get any real life experience input from anyone, I deflated one of the original tires to 29 PSI (normally 39 PSI) which is calculated over the 25% drop margin.

Took it for a drive last night, about 6 miles, nothing.
Took it to work this morning, after about 15 miles, the low tire pressure alert came up, with the yellow and the TPMS amber light.

OK, what's the point in the way it's operating. If you had a tire slowly deflating on the highway it's going to be flat by the time this system detects it. Also if you have a low tire overnight in the garage, you won't know until you are 15 or more miles down the road????

Another oversight on Ford's behalf, so common and so frustrating this car has become. Not only that we are having to deal with TPMS with winter tires/rims because of the government mandate, we have to deal with a clearly inferior system on the Focus (ONLY Ford that operates this way) and then still have to deal with a fault after a few days with winter rims/tires. Beautiful!

My 2010 Fusion would alert before even pulling out of the garage when I had a nail in my tire that made the tire low pressure overnight.
 

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