Queens Village is approaching an MBRC of 10,000. The propulsion-related MBRC for both depots jumped in December 2004 (this is not as noticeable for Mother Clara Hale because of the longer data period prior to the change). The most common RCs for the propulsion system were related to the engine and the hybrid control system shutdown or problem indicator lights. Many of the shutdown indicators for the hybrid propulsion system did not necessarily mean there was a repair required for the propulsion system. Problems in other systems can also be indicated by the propulsion control system.
Miles Between Roadcalls (MBRC)
10,000 9,000 8,000 7,000 6,000 5,000 4,000 3,000 2,000
Dec-04 Feb-05 Apr-05
MCH Total MBRC QV Total MBRC
MCH Propulsion MBRC QV Propulsion MBRC
Figure 12. Hybrid Fleet Cumulative Average MBRC
Specific maintenance items that have been worked on the hybrid buses have been:
Radiator baffle—surge tank overflowing
Water in wiring/connectors
Engine grid heater relay
Water in engine from air intake
Issues with the triple pump
Power control system (PCS) internal coolant leaks; some modification to the cooling system was done.
Software upgrades; moved some of the propulsion fault codes from the dash display to be on the engine compartment display; changed signal processing to be more tolerant of wiring intermittent signals.
The entire Orion VII fleet (CNG and hybrid) is currently undergoing a warranty maintenance campaign to address the items listed above for both groups. This is a significant fleet campaign that is planned to be completed by the end of 2005.