30. The Chair and the secretary of the HDH group introduced GRPE-68-14 on the HDH work progress. The HDH Chair summarized the fifteenth and sixteenth group meetings. Having explained the status of validation test programmes, he announced that the validation expected to be completed by the end of March 2014. Following an overview of the remaining open issues, having confirmed that the official submission of the text amending UN GTR No. 4 is expected for June 2014 session of GRPE and having expressed his confidence about the possibility to meet this deadline, he announced that there is a risk of not being able to do so if the validation fails, or if the open issues not solved to the satisfaction of the group. In this case, an extension of the HDH informal working group mandate will be requested at the June 2014 GRPE session.

31. [The HDH Chair] focused on the draft amendment to UN GTR No. 4 (GRPE-68-12) by providing details on the definitions, the concept of hybrid powertrain family, the approach considered, the content of Annex 8 (hardware in the loop simulation method) and 9 (powertrains method), as well as amendments aligning UN GTR No. 4 with UN GTR No. 11. The endorsement of GRPE was needed on this last point, since this is beyond the original HDH mandate.

32. [The HDH Chair] announced that, contrary to what was announced in earlier GRPE sessions, the technical report could not be finalized and submitted at the current GRPE session because the work programme would not be completed by March 2014. He suggested that it will be submitted as informal document to the next GRPE session and concluded by asking the secretariat to reserve a room for half a day for the HDH meeting to be held in conjunction with the June 2014 GRPE session.

33. The expert from OICA emphasized the importance to clarify before the end of January 2014 whether the system work or the engine work should be considered for the development of the regulatory text. GRPE endorsed the proposal by the expert from Sweden to set up a meeting of interested stakeholders in the EC framework to solve this issue.

34. GRPE endorsed the proposal of the HDH Chair to widen the mandate of the group to include amendments aligning UN GTR No. 4 with UN GTR No. 11. GRPE requested the sponsor (EU) to submit an informal document illustrating the choice to widen the mandate to the March 2014 session of WP.29 and AC.3, amending document ECE/TRANS/WP.29/AC.3/29.