I was recently asked to look up part numbers for the various HICAS controllers, I thought I'd post my findings here as I couldn't easily find anything else online with this info. I hope this can help someone else in the future. Keep in mind HICAS was limited only to factory twin turbo models through the entire production run so the below details only relate to these models. Model Year: 1989-07 - 1989-12 Applicability: 2+0 & 2+2 Part number: 28505-43P00 Replacement: 28505-43P50 Appears there was a different part number for very early builds, likely Nissan changed manufacturer or design on the original unit as they are listed as interchangable. Model Year: 1989-12 - 1993-09 Applicability: 2+0 & 2+2 Part number: 28505-43P50 Then there was a part number change when Nissan went from hydraulic to electric HICAS. Model Year: 1993-09 - 1996-07 Applicability: 2+0 & 2+2 Part number: 28505-50P10 Model Year: 1996-07-01 - 1997-01-01 Applicability: 2+0 & 2+2 Part number: 28505-50P15 Interestingly, in 1997 the 2+2 got a new part number for the controller. Model Year: 1997-01-01 - 1998-10-01 Applicability: 2+0 Part number: 28505-50P15 Applicability: 2+2 Part number: 28505-49P10 Then at the end of 1998 for the 2k spec model, they got unique part numbers for each wheelbase. Model Year: 1998-10 on Applicability: 2+0 Part number: 28505-VP100 Applicability: 2+2 Part number: 28505-VP120
