The group started the discussion of doc. TPM-03-09_rev1 point by point in order to produce a text which can be distributed as an official document for the next GRRF meeting in February 2009. The discussion showed, however, that it is not possible to reach agreement on all items amongst all members of the group during this meeting. The items where no agreement was possible will be put in square brackets and left open for decision by GRRF. The chairman will produce a new revision of the draft regulation in accordance with the results of this meeting which will be submitted to Geneva by the German Government before November 14, 2008. (see doc. TPM-04-02).
A short report about the most important discussion items and their results is given below:
Scope
There was agreement that as a first step the regulation should only be applied to light vehicles. Category N1 and M1 up to 3,5t will be proposed. The regulation shall also be applicable to the approval of systems which will be retrofitted as separate technical units on vehicles in use.
Definition of TPMS
The definition will be reviewed with regard to the definition in ISO.
Definition of Tyre Pressure Monitoring Function
It will be decided later if this definition will be introduced.
Definition of Minimum cold tyre inflation pressure and In service operating pressure
Final decision later.
Tyre Pressure Loss Reminder System (TPRS)
There was no agreement about the introduction of TPRS. OICA proposed the introduction especially with regard to contracting parties who want to allow cheap systems on low price vehicles. The majority of the group, however, was against the introduction of TPRS. In order to make progress the chairman decided to produce the draft regulation without the chapters which are related to TPRS and to leave it to OICA to produce a paper for its reintroduction.
New test procedure
An expert of the vehicle industry made a presentation and explained the advantages of the new test procedure elaborated by ISO. After a long discussion some experts still had doubts whether the new test procedure is better than the old one. Several experts declared that they need more time to compare the old and the new procedure. As most government representatives were in favour of the old procedure the chairman will keep this procedure in the revised text. Nevertheless OICA may produce a paper for the introduction of the new procedure and a final decision can be made later.
Thresholds
The thresholds for safety warning (25%/150 kPa,10min) were agreed. The thresholds for CO2-reduction still need further discussion (percentage or absolute figures). ETRTO proposed 25% or prec – pmin + 20 kPa and OICA will check if this proposal can be accepted. 60 minutes are not appropriate in the eyes of the tyre manufacturers.
Malfunction detection
A manufacturer of TPMS proposed to reduce the detection time.