Problem: our tire pressure monitors are constantly warning that the pressure is incorrect on all four tires. I check the tires frequently and they are always at 35 or 36 psi. Is there an adjustment for this?

Part of the problem could be that the tires that came on the car (used) are poopy Sam's Club "Fierce Instinct" tires, but shouldn't the monitoring system be set for 35 psi regardless of what tire is on the rim?

2009 XF

 

I'm working on a similar issue soon. Been that way since I bought it. I found that if I aired them up to 40+, it would go away. But in the cold, the temp swings too much for that to be ok. I bought a use TPMS module that I'll replace, then I'll go after all of the tire sensors if it isn't fixed.

 

Jag has an update to the TPS system that solved the same TPS problem I was having.

 

Are you using any car power adapters (in the cigarette lighter)? When I used a cheap one in my Lexus, the TPS light would come on. The problem ended when I used a better one.

 

Any idea on the cost of the TPS update?

 

Cost me an hour of time, which I think was something like $150.
...of course, it didn't work. Next step is replacing the sensor module, then probably all of the sensors in the wheels.

 

The TPMS failure fault code popped up on my dash this recent cold spell. Here is what I have done so far.... with the vehicle running, I let out the air in the RF tire. The system then detected the RF tire air pressure was low and flashed the car icon with the RF tire highlighted. I refilled the RF tire and proceeded to do the same to the other three tires. This eliminated the possibility that one of the TPMS sensors inside the tires was bad. Now, I think that the main module is faulty. My question now is, can this module be installed without any special programming or is this something thatwill need to be done at the dealership?

 

Mine has been doing the same thing for several months now, if a tire goes low it just keeps alerting a different tire a few minutes. 09SC

 

Just replace without any reprogramming, all parameters for TPMS proper work in CCF file

 

Ok, does anyone know where the module is located? And about how long would it take to replace? If it's a. Job the service department can do in an hour it's worth it to me for them to do it, but if they are going to take their sweet time then I might as well save a Saturdays worth of flight time and do it myself.

 

As I remember it must be under front right seat, under carpet.

 

It has two housing connectors:
C3MC39A and C3MC39B

 

Does the warning float from wheel to wheel? If so get them to reflash the software and it'll sort it. There was a tsb issued on this. Dealer should be doing it free of charge but they might charge an hour labor at the very most.

 

No it stays constant showing "Tyre pressure monitoring system fault". Does not cycle through each wheel. I deflated each tire to insure the sensors were not the problem. As soon as I deflated a tire, it would show up on the message screen. I then reinflated the tire and the image disappeared, but the fault message was still there. Did that to all four tires. All four sensors were picked up, so it must be the module. If I take it to the service department, they will charge me the $150 hourly rate to reflash, then if it does not work, I will end up there again for them to replace the module. My extended warranty will cover it but I have a $200 deductible. I will price the module and decide whee to go from there.

 

I've had that fault before but it cleared by locking and unlocking the car (was just a glitch probably due to my old battery). If it's staying on constantly for days then yeah it's the module. Pay the $200 deductible and get it fixed. It'll be way more than that to get it fixed out of warranty.

 

I've been fortunate with my experiences with the TPMS..On my Hummer it took about 6 years before my TPMS fault warning started to show up..Turns out the little watch battery in the tires Pressure transmitters were getting weak..Seems the colder the weather got is when it started happening until the fault was on most any time...When I had new tires put on I had them replace the TPMS tire transmitters..Cured

In the Jag..I got a notice that Left rear tire was LOW..Looking at it it appeared okay...Checking it with a tire gauge it showed 10 PSI under the rest...Found a small nail in the tread..So the Monitoring system has not let me down and who knows how long I would have driven on a soft tire before I noticed it being almost flat, perhaps damaging the tire.

 

TPMS wiring diagram

 

Do you know if they are the OEM sensors or aftermarket ones? If they are OEM the batteries in the sensors might be starting for fade on a 2009 car like yours.
If they are aftermarket then that could be the issue - my technician told me that they have had a lot of issues with non OEM tpms sensors working intermittently with the system. Even if they are correct 315MHz units

I have OEM sensors on my OEM wheels that have my winter tyres and they work perfectly. I have generic 315MHz sensors in the summer wheels and they give the same error that you have. It comes on continuously for anything from a day to multiple days in a row and then disappears again for a week or so before coming back. I took it to a tyre shop who checked the modules are all transmitting ok. And the car works fine on my winter wheels with original sensors so hard to believe the module is faulty.

Would love to hear if you manage to find a solution. I've found it very frustrating as it should be a simple technology

 

I've been lucky enough to have access to the SDD software and a knowledgeable operator, so while I was having other changes made to various management systems I had my TPMS turned off. I'm in the camp which believes this system is far more trouble than it is worth, if you have a major puncture or blowout surely you will sense it, and if you have a slow leak (eg from an embedded nail) then a manual pressure check and visual inspection should find it. I check my tyre pressures once a week and inspect the tyres once a month.

 

You are the exception to most everyone on the road. Even though I had a random TPMS issue caused by my USB charger (that the forum helped me fix ), I really appreciate the fact that I can basically ignore my tires and the TPMS will keep me safe until I check them. Which is usually every couple of months, or when the TPMS says that they are low.