achieving engine braking effect while also storing the pressure in the exhaust manifold again using the exhaust brake shutter ready for the next repeat of the cycle. Version 98 (1998–2002) In conjunction with the introduction of FM series in 1998, Volvo had facelifted existing FH series with minor modifications to the cab but major upgrade to the electrical system, engine, and gearbox. The so-called TEA (Truck Electronic Architecture) introduced a technical solution to possibility of various electronic control units to work and communicate with one another. The systems have been linked using two data buses or data links which allowed control units to exchange relevant information over the data network. Electronics TEA is a computerized control and monitoring system which is used to control and coordinate the various functions of the vehicle main components. The control units communicate over what is known as CAN at two speeds SAEJ1587/1708 @9600 bit/s and SAEJ1939 @ 250 000 bit/s where up to eight Electronic Control Units were used to control various functions. A J1939 data link is used for mission-critical rapid communication among ECUs and J1587/1808 is used for diagnostic and programming links as well as "slow" communication e.g. for backup purposes. The new instrument cluster included an LCD panel to show information or diagnostic messages from the systems broadcast via the J1708 data link. D12 facelift The original D12A engine was considered as a rather conservatively power rated and expectations of higher power output from such an engine design were always at the mind of not only the designer but customers alike. The D12C differs from an earlier version substantially with a completely redesigned engine head, timing gears, and addition of bottom end of reinforcement with a stiffening subframe to cope with increased power output to . Gearbox The gearboxes were based on the previous SR1900 series and shared the same number of gears and gear change pattern. The SR2400 series gearbox was discontinued and replaced with the now same model shared across the entire FH and FM range. Torque increases from 1900 Nm to 2500 Nm were due to changes to the machining of the gears as well as the use of the new type of narrower synchromesh mechanism allowing increased gear width. The single control housing and the synchro-mechanism reduced the gearchange effort by about 50%. The control housing was also identical for left and right-hand drive versions reducing overall