TPMS sensor replacement procedure

[H4wkeye]

My front left tyre TPMS sensor is wonky. From time to time I'd get "Tyre pressure not monitored" warning on the dash. Other times it shows OK. Anyway, I got a replacement, so I was wondering what is the procedure to replace it properly? I have a friend that can install it, he works at at tyre shop.

[GiveMeABreak]

It needs both the exciter tool and the Diagnostic tool (like Diagbox). First the sensor is activated using the exciter tool (as they are supplied dormant to prevent premature battery wear), then the new sensor is paired / programmed to the vehicle's TPMS ECU.

Be advised that all the other wheel sensors may need to be checked at the same time as Citroen had to re-pair all my sensors when one was paired on its own and kept failing. It took three tries then they realised they needed to do all 4 at the same time to prevent the errors.

[H4wkeye]

So basically after the actual installation it needs to be programmed in via diagnostics. Gotcha. Does it have to be Diagbox? I believe he said they have some universal diagnostic, Delphi.

[Paul-R]

There are certainly specialist tools available for tyre bay use with TPMS systems.

When I had tyres fitted at Costco a few years ago they pulled the old tyres off the rims without worrying which one came from where. Later they showed me on a hand-held device that plugged into the EOBD port that all TPMS units were showing as being active and in the correct position.

They didn't show it to me but there must have been an exciter involved as well.

[MGmike]

It very much depends on the make of sensor you have bought/fitted. I use Autel MX sensors as these can be programmed to match the original sensor ID and therefore there is no requirement to reprogramme via the EOBD port. An OE VDO sensor will need to be excited and programmed as mentioned above. However, there is a possibility it has been shipped in a state (park) that doesn't need the exciter step. And before anyone jumps in and says that never happens... I have received at least one in this state.

[H4wkeye]

The one I got was sent by a friend that had a few extra used ones in working conditions. They are for C5 X7.

[MGmike]

Ah, in that case you shouldn't need the exciter but you will need a reader to get the ID and a tool to program that to the ECU.

[H4wkeye]

Do I need to read the id before mounting it or can it be done after?

[GiveMeABreak]

After - Diagbox recognises the code when it is activated and pairing. I can't speak for the other systems mentioned here that you may decide to use though.

[H4wkeye]

Alright, thanks Marc! I'll look into it.

[MGmike]

Do I need to read the id before mounting it or can it be done after?

After - Autel reader (and probably other manufactures) will read the code of mounted sensors.

[H4wkeye]

I just randomly noticed today when I hit the check button all my TPMS showed as dashes. A week or so ago when I checked something they showed OK. Also it'll randomly start working again once I get a warning on the dash saying tyre pressure not monitored (cuz I need to change the front left one). Then it showed the other 3 as OK and the front left as not being able to read. Wonky receiver? Or maybe the bad sensor causing some glitch.

[GiveMeABreak]

I think I mentioned before, best to re-pair the whole 4 at the same time when you get the replacement done as this is what I had to do when one of my front ones kept playing up (all new by the way). Even the Citroen tech, after 3 attempts at pairing the troublesome one realised he had to do the lot at the same time and that cured the problem at the fourth attempt.

[H4wkeye]

I'll make sure to mention that once I finally get it done. Cheers Marc.

[H4wkeye]

This has been long overdue but I plan to finally change the sensor soon. Can you do the reprogramming via another diagnostic tool, such as Delphi or Autel? Should I just clone this sensor and then write it onto the new one? The new sensor is a used one, Citroen OEM but it's still working. (For C5 X7 models)

Also, checking the sensor via diagnostic showed that it couldn't read/receive signal from it DTC, so I guess it's giving out. Sometimes it works fine for a while, other times it keeps showing warnings.