New Ducato

[Derek Uzzell]

Ashpark - 2015-07-06 9:26 AM

 

Thanks Derek, yes it's an A/S Neuvo. I would be happy to reduce the psi but another owner of the same vehicle has reported that he tried that and has been unable to get the warning to turn off, even with the tyres reinflated to the original settings. I've been pretty disappointed with the technical advice on this from Peugeot, they originally suggested I ask at my local Peugeot service centre :-| . My request to them was for information on the operation of the system and tolerances, above is what I got after three emails.

 

I’m guessing that you are referring to the last entry in this Caravan Club discussion

 

http://tinyurl.com/oajchsj

 

The author (Newydd) claims that the 72.5psi/79.7psi pressures shown on his 2015 Boxer-based Auto-Sleepers’s door plate are for a ‘generic’ Boxer and not for a motorhome nor for Continental “VancoCamper” tyres. In fact the exact opposite is true – the high pressures are recommended specifically for recreational vehicles fitted with ‘camping-car’ tyres.

 

Lowering Newydd’s tyre pressures to 65psi/75psi did not result in a TPMS alarm, whereas reducing the pressures further to 60psi/70psi did. One should perhaps anticipate a TPMS calibrated to 70psi-80psi to have a reasonably wide window within which the system will ‘consider’ the pressure to be normal. I’m surprised though that, when Steve928 used 50psi/53psi (that’s a whopping reduction of 27psi for the rear tyres) his Bailey’s TPMS failed to alarm and it would be interesting to know what pressures his motorhome’s TPMS is calibrated to.

 

Steve points out that, following a TPMS alarm and the tyre being reinflated to a pressure that should not trigger the TPMS, the vehicle needs to be driven for a while before the alarm cancels itself. Newydd does not say if, having reinflated his motorhome’s tyres to higher pressures, the vehicle was actually driven – just that the TPMS continued to alarm when the motorhome was started.

 

[Ashpark]

Derek, no a different forum but possibly the same author?

 

I asked him yesterday and he said that after 90 miles at the higher recommended 5 bar and 5.5 bar the TPMS was still displaying the warning. I take your point on tolerances, it does seem odd that Peugeot and Continental are so far apart on what they recommend. I also wonder what the implications might be for temporary under inflation of a tyre in future, will it always require a visit to a Peugeot dealer for the CPU to be reset? My email correspondence with Peugeot continues on this but I'm not holding my breath.

[Brian Kirby]

Keithl - 2015-05-19 4:01 PM

 

I cannot find a link to load tables for Michelin but here is a link to Continentals data... Link.

 

The load data for 215/70 R 15 CP tyres is the last row of pages 72 and 73. It may be easier to print the 2 pages rather than try and follow across the row. [RED]You will need to look at the row marked 'FA S' for both axles as your MH is front wheel drive and 'RA S' is only for rear driven axles.[/RED]

 

I agree with other comments that I would run at suitable pressures for actual axle loads but that is purely my opinion and no recommendation whatsoever! I do for our MH but it is on larger tyres and also RWD so my pressures will be irrelevant.

 

Keith.

 

Apologies Keith, but while picking up on the latest posts on this string, I looked back and was puzzled by the above statement, highlighted in red.

 

Reading Conti's notes to the Databook, I couldn't find any reference to the rear axle pressure being applicable to driven rear axles (i.e. RWD) only, so I 'phoned Conti's technical department for clarification.

 

Their answer was categorical: the pressure for load tables in their Databook are based purely on the mounting position of the tyre, WHETHER OR NOT THE AXLE IS A DRIVEN AXLE.

 

This is important, since anyone applying front axle tyre pressures to rear axle tyres would be substantially under-inflating the rear tyres.

 

The only crossover point in the table for 215/70 R 15 CP tyres is at their max load of 2060kg, where the front axle pressure is 4.75 bar (69 psi), and the rear axle pressure is 5.5 bar (80 psi). The consequence of following the above advice would be rear tyres that were under-inflated by 0.75 bar (11 psi), or about 14%. This percentage difference appears approximately consistent for all axle loadings.

 

Conti reiterated their standard advice that, if unsure of the actual axle loads, the tyres should always be inflated to the motorhome manufacturer's recommended pressures and, where pressures are being adjusted for actual axle loads, to use the nearest listed pressure above the actual load. Slight over-inflation will have no impact on tyre performance or wear patterns, whereas under-inflation increases the risk of sudden blow-out - the greater the under-inflation, the higher that risk.

[Derek Uzzell]

Michelin’s tyre safety and utilisation advice document can be found here

 

https://www.michelin.co.uk/content/pdf/TC_Safety_Guide_UK.pdf

 

with a motorhome-related section beginning on Page 4.

 

In 2003 the ETRTO allowed tyre manufacturers to use the “CP” (Camping Pneu) marking for tyres aimed at the motorhome sector. It needs to be emphasised that (according to Michelin) the “CP” standard merely relates to the marking and has no technical implications regarding how a CP-marked tyre performs on test or on the road.

 

I recall that there was initially confusion as to whether the ETRTO advice that a 5.5bar inflation pressure should be used when CP-marked tyres were fitted to a motorhome’s rear axle only applied when a driven axle was involved. I’m not sure where that idea came from, but as the vast majority of motorhomes in 2003 (and nowadays) that were fitted with CP-marked tyres had a non-driven rear axle, it would have been very odd if ETRTO had singled out just a tiny minority of vehicles. As Michelin’s document states, the 5.5bar-related advice applies only to motorhomes with a ’single fitment’ rear axle (“RA S” in Continental’s handbook) and not to a ‘twinned wheel’ rear axle (ie. an axle with two wheels on each end) and it’s irrelevant whether the rear axle is ‘live' or ‘dead’.

 

As far as I’m aware ETRTO standards are not available on-line and the documents are not cheap to buy. It’s certain that Michelin and Continental (and probably Pirelli) technical staff will have access to the ETRTO standards, but I’m not sure how much that would help regarding why the ETRTO (apparently) insists on the 5.5bar rear-axle pressure for CP-marked tyres. Michelin has a rigid stance about this, whereas Continental is more flexible. If asked, Michelin will tell you 5.5bar for their CP-marked tyres fitted to a single-fitment rear axle irrespective of the axle loadings, while Continental will provide a rear-axle pressure for their CP-marked tyres based on a stated axle loading. In both cases, if the advice regarding inflation pressure conflicts with the motorhome manufacturer’s recommendation it’s the responsibility of the vehicle owner whether or not to follow it.

 

(A link to the Boxer TPMS being discussed on the ASOF)

 

http://www.autosleeper-ownersforum.com/t14872-tyre-pressure-monitoring-system-tpms

 

 

 

[Steve928]

Derek Uzzell - 2015-07-07 8:16 AM

Steve points out that, following a TPMS alarm and the tyre being reinflated to a pressure that should not trigger the TPMS, the vehicle needs to be driven for a while before the alarm cancels itself.

 

That's not quite correct as I haven't yet been able to generate a TPMS low pressure alarm, despite reducing the pressures as far as I dare, so I have no information concerning how this type of alarm clears or is cleared.

 

The alarm that is generated by running without TPMS valves (or presumably with defective valves or valves low on battery power) or by fitting different valves is 'TPMS unavailable' accompanied by the TPMS warning light constantly lit. It is this condition that takes approximately 3 miles to first appear and then be cleared.

I suspect that this is because the valve-sensors enter sleep mode once parked, to preserve battery power, and are only reactivated by the rotation of the wheels; the body computer therefore has to allow a certain timeout value for all the wheels to report in. Once the system is up and running I wouldn't expect low pressure alarms to be subject to any such delay.

[Derek Uzzell]

As far as I can make out the information in the Peugeot Boxer handbook regarding the TPMS (“TYRE UNDER-INFLATION DETECTION” in Peugeot-speak) is pretty sparse.

 

It would be reasonable to assume that the same system is used in Fiat Ducatos. The handbook for Ducato X290 vehicles can be displayed/downloaded via this webpage

 

http://tinyurl.com/o6yqqvk

 

I have copied below the TPMS-related section

 

...................................................................................................................

 

TPMS (TYRE PRESSURE MONITORING SYSTEM)

(for versions/markets, where provided)

 

DESCRIPTION

The tyre pressure monitoring system

(TPMS) warns the driver of low tyre

pressure on the basis of the cold

inflation pressure prescribed for the

vehicle.

 

Changes in outside temperature may

cause tyre pressure to vary. This means

that a decrease in the outside

temperature corresponds to a decrease

in the tyre pressure.

 

Tyre pressure must always be adjusted

according to the cold inflation pressure.

 

Cold tyre inflation pressure is the tyre

pressure after letting the vehicle stand

for at least three hours or a travel

shorter than 1.6 km after an interval of

three hours.

 

The cold tyre inflation pressure must

not exceed the maximum inflation

pressure value printed on the side of

the tyre.

 

The tyre pressure also increases while

driving the vehicle: this is a normal

condition and does not require any

adjustment of the pressure.

 

The TPMS continues to advise the

driver of the low tyre pressure condition

until this is corrected; the warning

continues until the pressure

corresponds or exceeds the pressure

prescribed for the cold tyres. When the

tyre low pressure control warning

light switches on constantly, the

inflation pressure must be adjusted until

it reaches the pressure prescribed for

cold tyres. After the automatic update

of the system, the tyre pressure control

warning light switches off. You may

need to drive the vehicle for about 20

minutes at a speed higher than 20

km/h to allow the TPMS to receive this

information.

 

NOTE

- The TPMS does not replace the

normal tyre maintenance service and

does not indicate any fault in a tyre.

 

- Therefore, the TPMS should not be

used as pressure switch while

adjusting the tyre inflation pressure

 

- Driving with insufficient tyre pressure

causes their overheating and can

result in tyre failure. The low inflation

pressure reduces fuel efficiency

and tyre tread life and may also affect

handling and braking performance

of the vehicle.

 

- The TPMS does not replace the

correct tyre maintenance. It is up to

the driver to maintain the correct tyre

pressure level measuring it with a

suitable pressure switch. This is

necessary even if the decrease in the

inflation pressure value does not

cause the tyre pressure control

warning light to switch on.

 

- The TPMS warns the driver of any

condition of insufficient tyre pressure

If this drops below the insufficient

pressure limit for any reason including

low temperature and normal

pressure loss of the tyre.

 

- The seasonal temperature changes

affect tyre pressure.

 

The TPMS uses wireless devices with

electronic sensors mounted on the

wheel rims to constantly monitor the

value of tyre pressure. The sensors

mounted on each wheel as part of the

valve stem transmit various information

of the tyres to the receiver module, in

order to calculate the pressure.

 

WARNING - Monitoring and maintaining

the correct pressure in all four tyres

are particularly important.

 

TYRE PRESSURE MONITORING SYSTEM - LOW PRESSURE WARNINGS

The system warns the driver if one or

more tyres are flat by switching on

the warning light on the instrument

panel (together with a warning message

and an acoustic signal).

 

In this case, stop the vehicle as soon as

possible, check the inflation pressure

of each tyre and inflate to the cold tyre

pressure value prescribed for the

vehicle. The system will automatically

update and after receiving the tyre

pressure update the tyre pressure

control warning light switches off. You

may need to drive the vehicle for about

20 minutes at a speed higher than 20

km/h to allow the system to receive this

information.

 

TPMS OPERATION FAULTS

The system fault is indicated by

warning light which first flashes for

75 seconds and then stays on steadily.

This can occur in any of the following

situations:

 

- Interference caused by electronic

devices or radio frequency emissions

similar to those of the TPM sensors.

 

- Application of tinted films which

interfere with the signals of the radio

waves.

 

- Presence of snow or ice on the

wheels or the wheel arches.

 

- Use of snow chains.

 

- Use of wheels/tyres not equipped

with TPM sensors.

 

- The space-saver wheel is not

equipped with the tyre pressure

control sensor. Therefore, the tyre

pressure is not controlled by the

system.

 

- If the space-saver wheel replaces a

tyre with a pressure lower than the

insufficient pressure limit, an acoustic

signal will be emitted and the warning

light will switch on at the next

ignition cycle.

 

- When the original tyre is repaired or

replaced and it is mounted back on

the vehicle to replace the spacesaver

wheel, the TPMS will update

automatically and the warning light

will switch off, provided that the

pressure of none of the four tyres is

below the insufficient pressure limit.

You may need to drive the vehicle for

about 20 minutes at a speed higher

than 20 km/h to allow the TPMS

to receive this information.

 

IMPORTANT INFORMATION

WARNING

The TPMS is optimised for the

original tyres and wheels

provided. TPMS pressures and

alerts have been defined

according to the size of the tyres

mounted on the vehicle. Using

equipment with different size,

type or kind may cause irregular

system operation or sensor

damage. Non-original spare

wheels can damage the sensor.

Do not use tyre sealant or

balancing weights if the vehicle is

equipped with TPMS as these

may damage the sensors.

 

If the system signals a pressure

decrease on a specific tyre, it is

recommended to check the

pressure on all four tyres.

 

TPMS does not relieve the driver

from the obligation to check the

tyre pressure every month; it is

not even to be considered a

replacing system for maintenance

or a safety system.

 

Tyre pressure must be checked

with tyres cold. Should it become

necessary for whatever reason

to check pressure with warm

tyres, do not reduce pressure

even if it is higher than the

prescribed value, but repeat the

check when tyres are cold.

 

The TPMS cannot indicate

sudden tyre pressure drops (for

example when a tyre bursts).

In this case, stop the car, braking

with caution and avoiding abrupt

steering.

 

The system only warns that the

tyre pressure is low: it is not able

to inflate them.

 

An insufficient tyre inflation

increases fuel consumption,

reduces the tread duration and

may affect the capacity of driving

safely.

 

Always refit the valve stem cap

after inspecting or adjusting tyre

pressure. This prevents dampness

or dirt from entering the valve

stem and thus the pressure

control sensor from being

damaged.

 

The tyre repair kit (Fix&Go)

provided with the car (for

versions/markets, where

provided) is compatible with the

TPMS sensors; using sealants not

equivalent with that in the original

kit may adversely affect its

operation. If sealants not

equivalent with the original one

are used, it is recommended to

have the TPMS sensor operation

checked by a qualified repair

centre.

..................................................................................................................

 

It will be seen from the above that (at least where the Ducato is concerned) in the event of the pressure in a tyre reducing sufficiently to cause a TPMS alarm, if that tyre is then reinflated to the ‘correct’ pressure the TPMS should then reset itself automatially and the alarm cease.

 

The Ducato X290 handbook also contains Cold Tyre Inflation Pressures data listed by TYRE SIZE, VEHICLE USAGE and INFLATION PRESSURE (Front tyres in bars - Rear tyres in bars)

 

..................................................................................................................

 

215/70 R15

3000 GVW (*) with basic tyres, except PANORAMA 4,0 4,0

3300 GVW (*) / 3500 GVW (*) with basic tyres 4,1 4,5

 

215/70 R15

PANORAMA with basic tyres 4,1 4,5

 

225/70 R15

3000 GVW (*) with oversized tyres, except PANORAMA 4,0 4,0

3300 GVW (*) / 3500 GVW (*) with oversized tyres 4,1 4,5

 

225/70 R15 C

Winter tyres M+S class C on Camping vehicle 4,3 4,75

 

225/70 R15

PANORAMA with oversized tyres 4,1 4,5

 

215/70 R15 CP

Range with Camping tyres 5,0 5,5

 

215/75 R16

For all versions/trim levels 4,5 5,0

 

225/75 R16

For all versions/trim levels excluding the lines below 4,5 5,0

 

225/75 R16 C

Winter tyres M+S class C on Camping vehicle 5,2 5,2

 

225/75 R16 CP

Camping tyres 5,5 5,5

 

225/75 R16 CP 118

4400 CVW Maxi range with Camping tyres (for versions/markets, where provided) 5,5 6

 

..................................................................................................................

 

To summarise, the advised front-tyre/rear-tyre pressures (in bars) for Ducato X290s with CP-marked (“Camping”) tyres are

 

215/70 R15 CP - 5.0(front) - 5.5(rear)

 

225/75 R16 CP - 5.5(front) - 5.5(rear)

 

225/75 R16 CP 118 - 5.5(front) - 6.0(rear)

 

 

 

[Ashpark]

Once again, thanks Derek. That's very helpful and seems to make the case for following their recommendations on tyre inflation levels. It does, for me anyway, raise further questions about tyre balancing (given that no weights should be used) and the use of appropriate sealants. I wonder how many of the usual tyre fitting suspects will be au fait with the technical remifications of replacing tyres on vans with TPMS in place, given that my local Peugeot "technician" took several hours to reprogramme the CPU after the faulty sensors were replaced.

 

Oh well, only 2 years and 10 months until it's first MOT :-D

[Derek Uzzell]

Although the Fiat Ducato X290 handbook says "Do not use tyre sealant or balancing weights if the vehicle is equipped with TPMS as these may damage the sensors”, it goes on to say that the sealant in the “Fix&Go” repair kit is compatible with the TPMS sensors.

 

Although it will definitely be the case that certain methods of wheel balancing would harm TPMS sensors fitted to the base of tyre-valves, the standard practice of attaching external balance-weights to a wheel should really have no impact on a TPMS. It would be miraculous if, when a tyre is being fitted to a wheel, the combination could always be adjusted so that it is in balance without any weights being added to achieve this. I assume there’s was a reason for the author(s) of the Fiat handbook to insert the caveat about the balancing weights, but I’ve no clue what that was (and there’s little point asking Fiat!!)

 

The type of TPMS involving a sensor on the base of a tyre-valve radically increases the complexity of the tyre-fitting procedure. Schrader (who quite likely supply the TPMS valves for Boxers/Ducatos/Relays) go into great detail about how wheels with TPMS valves should be treated, and valve-fitting that could in the past be considerded a semi-skilled job now seems to approach rocket science. This US website should be educational.

 

http://www.tpmsmadeeasy.com/installing_schrader_tpms.php

[Steve928]

Derek Uzzell - 2015-07-08 8:15 AM

 

You may need to drive the vehicle for about 20

minutes at a speed higher than 20

km/h to allow the TPMS to receive this

information.

 

 

That does seem a very strange requirement. As a software engineer working with embedded systems, communications and remote sensors every day I'm struggling to see why such a slow response time has been implemented.

 

Regarding balance weights, all six of my TPMS steel wheels came fitted with standard weights. The 2 alloy wheels that passed through my hands were also balanced in the usual manner i.e. with stick-on weights.

[everhopeful]

From the info helpfully provided by Derek it seems the X290 TPMS operates in some ways the same as the Tyrepal system. i.e. wireless transmission from the sensors to a central point somewhere. That being the case I wonder if the X290 sensors would be recognised by a Tyrepal box. There is no doubt a very narrow frequency band allocated to TPMS devices.

If that did work the Tyrepal system offers full control over the high/low pressure alarms. In the real world it probably wouldn't work, but I wonder when a 3rd party will produce an add-on box to replace the user-unfriendly standard system.

I imagine all control is removed from the end-user to stop people fiddling and causing warranty complaints, but it leaves us with a "box ticked" system that could be so much better. *-)

[Derek Uzzell]

I suspect that the caveat in the Ducato manual’s TPMS section regarding “balancing weights” is a red herring. As I said earlier, there are wheel-balacing systems that do not use externally-fitted weights (examples below)

 

http://www.innovativebalancing.com/

 

http://www.easy-balance.com/en/what-is-easy-balance.php

 

and it’s easy to imagine that these might harm TPMS sensors mounted on the base of tyre valves.

 

It’s interesting to compare the TPMS information in the Ducato handbook (and the on-line forum comments about the Peugeot Boxer’s system) with the TPMS advice in the handbook for the latest Ford Transit.

 

http://tinyurl.com/qxn2a7t

 

It will be seen that (like Ducato/Boxer) the Transit’s TPMS uses sensors attached to the underside of the tyre-valve, but the system also includes a simple resetting procedure that would appear to allow the vehicle user to ‘customise’ the vehicle’s tyre pressures.

 

This video-clip shows a Toyota car’s defective original-equipment TPMS on-tyre-valve sensor being replaced by a Schrader ‘universal’ EZ-Sensor and graphically demonstrates the complexity of the procedure

 

https://www.youtube.com/watch?v=2MXEbulpQ7M