TPMS!! Elddis Envy 120 2018

[Barry Peake]

Following recent chats, I have now had the Elddis 120 accord weighed (twice) checked the tyre pressures as they were ,on collection of the vehicle from the dealer, and found, despite the door pillar quoted pressures (front 72 and rear 80) that the pressures were 67 all round.

I then by appointment, visited a Peugeot dealer and asked that the TPMS system be altered to a range between 60 and 80 psi "no problem" sir but 10 min later 'I'm afraid the system is set to the 72 front and 80 rear and won't let me reset it".

So I have a van with tyre pressures of 70 psi all round and have now covered 300 plus miles without any warning lights or bells but I am at a loss if the system says 72 and 80 how I have been able to change to 70 all round.

I have decided to put up with the hard ,bouncy ride but dread to think what will happen if we get a puncture exactly what the TPMS system will make of a different pressure if there is a difference on fitting a spare.

I could continue to pursue the matter but the dealers workshop told me they had no idea and to contact a Peugeot dealer no doubt Elddis will refer me to continental tyres which is where I got most of the helpful info from.

[Steve928]

It's because a TPMS alarm is triggered at 25% deflation.

As yours is set to 72F 80R it would trigger an alam at 54F 60R, hence your 67 is OK.

 

Before I reset my TPMS values mine was also set to 72F but I could run 54F with only the occasional alarm on very cold mornings or upon descending an alpine pass.

[Derek Uzzell]

Steve

 

My Fiat Ducato-based motorhome does not have a TPMS, and my Skoda car’s TPMS is the indirect type that exploits the vehicle’s ABS sensors (and there’s a ‘reset' button to allow for tyre circumference and tyre-pressure variations.) Consequently (and fortunately!) I’ve no hands-on experience of the direct TPMS that has been factory-fitted to recent Peugeot Boxer-based motorhomes.

 

I note from Barry’s posting above his Peugeot dealer was able to tell him that his Elddis motorhome’s TPMS software recorded 72psi and 80psi for the vehicle’s front and rear tyres respectively. So it seems that the stored ‘recommended’ pressures can be confirmed if the Boxer’s TPMS can be interrogated.

 

You’ve said “...a TPMS alarm is triggered at 25% deflation” and this tallies with Schrader’s comment

 

"When your TPMS warning light comes on, please exercise caution. This means that one or more of your tires may be at least 25% below recommended inflation pressure."

 

on this link

 

https://www.schradersensors.com/en-gb/driver-education/what-do-when-your-tpms-light-turns

 

There will need to be built into the Boxer TPMS an acceptable pressure-reduction from the stored pressures to allow for the effect of cold weather conditions. This reduction could be based on a specific value (eg. 60psi) or a percentage (eg. 25%) and - if the stored ‘recommended’ pressure were 80psi - both methods should trigger a TPMS alarm when the 80psi stored pressure dropped to 60psi.

 

Did you actually manage to reset your Bailey’s TPMS stored pressures yourself, or did a Peugeot agent need to be involved? When a Boxer’s TPMS is interrogated, I’m just curious about what (if any) information is accessible about the acceptable pressure reduction, as there have been observations by Boxer owners (examples here)

 

https://www.caravanclub.co.uk/club-together/discussions/information-technical-tips-advice/motorhomes/2017-peugeot-boxer-low-tyre-pressure-warning-lamp/

 

that suggest the pressure-drop that provokes a TPMS alarm can be relatively small (a 10psi drop is instanced) or even minimal, with one owner saying "The lowest I can get mine on the rears are 78psi...” Plainly, in both instances, the low-pressure alarms could be being triggered because the ‘recommended’ pressures that were stored in the vehicle’s TPMS were higher than the 72/80 values that might be anticipated, but that hypothesis could only be checked by interrogating each system.

 

I assume with a Boxer’s TPMS that there’s no means to set the ‘recommended’ pressures to a range (as Barry would have liked) - if he did have the TPMS reset, he’d need to choose a specific pressure for his motorhome’s front tyres and anothe specific pressure for the rear tyres. There’s also the possibility that his Boxer’s TPMS isn’t functioning properly (as I believe was initially the case with your Boxer-based Bailey) and won’t produce alarms however much Barry lowers the tyre-pressures, though (presumably) the Peugeot dealer would have been able to check and confirm that his TPMS was working correctly.

[Steve928]

Apologies for the delay in replying, Derek.

 

Yes, I bought the cables, converter box (for PSA vans based upon Fiat platforms such as the Doblo and Ducato) and software to enable me to read and write the TPMS values myself. This Peugeot Planet/Citroen Lexia kit cost around £80 or can be had for a bit less if ordered from China.

The values held in the system are the actual pressures to be run. One front axle value and one rear axle value. Presumably in the case of a tandem axle van both rear axles are expected to be at the same pressure. The BSI, presumably with code from Schrader, takes care of the 25% deflation threshold and any other parameters that it has available such as, perhaps, wheel internal temperature.

 

As you have noted, my system was set up incorrectly with rear wheel pressures set to 0 (disabled); it was one of the first TPMS-equipped cabs to have passed through the Al-Ko conversion process. The front value was the standard 72psi (actually the Bar equivalent) which allowed 54psi to be run with just the occasional alarm.

When an alarm is triggered is the only time that the system displays the detected pressure and there were a few strange happenings, such as an alarm 200 miles into a journey with hot tyres and pressure comfortably above the 54psi threshold. I gave up trying to fathom out what was happening and just put all alarms down to the catch-all of running too close to the trigger threshold.

That seems to have been the case because since configuring the system with the actual pressures being used some 2 years ago the TPMS has been trouble-free. Trouble-free enough in fact to make me glad that I have it!

[Derek Uzzell]

Thanks for the feed-back.