Electronic reservations, new seats and coloured PIS (like those in the refurbished 158's).
The minimum requirements for Northern Connect units are:
(a) air conditioning and heating systems that are designed to operate effectively and reliably within the range of ambient temperatures normally experienced in the north of England throughout the year;
(b) fixed or folding tables at a minimum of 90% of seats;
(c) power sockets or USB charging points with a minimum of one socket provided for every two seats;
(d) adequate space for luggage which takes account of the fact that the Northern Connect Passenger Services shall be operated to and from airports and other significant tourist venues;
(e) toilet facilities (including, baby-change facilities and toilets which are Controlled Emission Toilets);
(f) full compliance with the accessibility requirements in the Railways (Interoperability) Regulations 2011 notwithstanding that compliance is not required by law until 1 January 2020; and
(g) electronic seat reservation systems;
Additionally all Sprinters plus the 319s, 333s and 170 must have the following work done:
(a) recovering of all seats and the replacement of all seat cushions;
(b) new floor coverings throughout;
(c) repainting of all interior panels;
(d) powder coating of all grab poles and rails;
(e) a clean compliant with the Deep Clean Specification;
(f) full exterior repaint (it being agreed that with regard to those Class 319s units repainted into the current Northern operator’s livery in 2015 or 2016 re-painting of those units shall be completed by 31 March 2023);
(g) fitting of Wi-Fi compliant with at least the Minimum Wi-Fi Service Requirements;
(h) fitting of at least one PRM compliant toilet with baby-change facility per multiple unit;
(i) fitting of LED lighting, with lighting intensity complying with EN 13272 ‘Railway Applications – Electrical Lighting for Rolling Stock in Public Transport Systems’;
(j) fitting of a passenger information system compliant with the Passenger Information System Specification;
(k) fitting of CCTV compliant with the Internal CCTV Specification;
(l) fitted with a driver advisory system to advise the driver on the most economical method of driving consistent with good timekeeping;
(m) fitted with forward facing CCTV;
(n) fitted to be “ERTMS-ready” so that when ETCS equipment needs to be installed in accordance with the Network Rail programme it can be done without needing intrusive works including because necessary wiring is in place and space for the equipment has been kept free as part of the refurbishment works.
So while Northern can go above the minimum requirements new seats and coloured PIS are not required.