Hi everyone,

Since I've had my brakes replaced a month or 2 ago, I've been getting a warning on my dash saying 'tyre pressure sensors not detected'. It is a 2015 focus, and I know that the sensor may have just run out of battery but wanted to know if it could have been anything to do with the brakes being replaced, and is there any way to know which sensor specifically would be causing the fault?

Thank you

Hi,

There isn't any reason why a brake change should affect tyre sensors. But if it happened immediately after then seems like more than coincidence?

Forscan might tell which sensor is failing. Or a tyre pressure sensor tool can detect which sensor no longer sends radio signals. If the sensors are original on a 2015 car then they're probably all about to fail anyway. If any of the tyres need replacing soon, I would wait until then and change sensors at the same time.

I have a 2016 Focus and have had the TPMS’s changed this week. I assumed battery(s) gone on at least one sensor when the not detected came up. I was able to check which one via one of the tools you can get (small grey coloured rectangular tool via amazon, not expensive) just out of curiosity really. It was confirmed on here that if the fault shows on MOT its a fail.

Thanks for the replies, I guess yeah it was just an unfortunate coincidence with the timing. I need some front tyres soon so I'll get them replaced at the same time.

I have the same problem, only had the car about 4 month's and it been showing ever sinse it was delivered, the seller (M cars in Poole) recons he had it fixed, enquired as it's got 6 month's warranty but it'd mean me driving to Poole or him having the car collected, we did the reset thing and it was ok for several days then it came back again, all tires are good and all at 35psi, apparantly the sensors and inside each rim so it means tire fitters removing each tire and a ***** big bill, resigned to doing it the old school way! stick a pressure gauge on and see what it says😁

As said earlier, I had mine replaced this week at an independent tyre fitters, I use them for tyres all the time they can be trusted etc. i purchased the sensors (about £20 each from ebay I got them)the 4 of them were fitted for £70 another £30 I think if I needed them to relearn the system but I done that myself. They are something like £35 each I think from Ford. I wouldnt have bothered changing them as I always check tyres anyway but its MOT fail if fault showing.

Didn't know it was a MOT fail! thanks for that, if you manage to disable that warning is it still a fail? hope thats not a daft question

You can get four for about thirty quid of Amazon and with a bit of ingeniuity and some brute force break the bead on the outside only and fit new ones yourself. It took me an afternoon a Yard of 14 MM studding and two bits of 4x2 to make a press in which the wheel was sandwiched. Not only could I do it myself for minimal outlay but there was no need to rebalance because the tyre remained in the same place on the rim. The old valve is pushed in, use silicone oil or grease, then the new one is pulled in with a valve pulling tool which costs about a fiver. Add in a programming widget and it all goes perfectly well. I did mine four years ago when I needed to fit smaller rims and it is still working fine.

About disabling the TPMS system, I asked this not so long ago which is when it was state d its a MOT fail. I'm sure I was advised it wasnt possible to disable the system.

When we purchased the C Max the TPMS light was on due to the fact that the batteries in all wheels had failed (64 plate). It had just passed an MOT with the light on - I asked an MOT tester why it would pass with the light on - his response was if the light is on yet no visible flat tyres then they cant fail it. I got fed up looking at the message every time I started the car so I have since had it disabled with forscan - It has since passed another MOT with no mention of TPMS. My mindset on this, If my 2007 mondeo doesnt have TPMS or my 20 plate renault master doesnt have it then why does a 64 plate require it ? A load of non essential crap to go wrong (as it does). Do yourself a favour and get it disabled.

The MOT testers manual is not very clear on this. It's easy for testers to misunderstand (as proven above!). But is also very difficult to fail a car where the TPMS has been completely disabled.

They are meant to fail cars where the TPMS is obviously faulty. They are not meant to fail cars where the TPMS only indicates a low tyre pressure. They are not expected to confirm a TPMS enabled light illuminating at start-up.

This is the exact wording from the MOT manual.

If you reset the system via the dashboard the warning light will go out for a number of miles/days while the system tries to relearn. You can get the MOT done during this time before the warning comes back on again!

If mine go again I might see about disabling them on my M3.5 Focus if its possible. I did use reset few times and it was actually a relief to not see the light on even if for 15 mins or so despite knowing not actually anything wrong with tyres. It 'll hopefully be at least 6yrs tho as theyve just been done. Hopefully I can confirm no MOT failure etc but if so easily enabled again with luck.

I've started getting this TPMS issue though seems really random. Doesnt come up every journey. I know that around every 10-15mins of doing 25mph+ the sensors are checked by the computer to see if it can detect them, but sometimes doesn't come up. Like you've said they probably just need replacing now as the sensors will be 9yrs old and the batteries have done well. At least you can just reset the message in the Settings. Thanks for mentioning about the MOT failure, I didn't realise that. Give me the olden days when you would walk around your car and check that the tyres looked okay!