Hi All,
I've got an issue with my brakes that requires some auxiliary vacuum which I've decided to use a UP28 electric pump. I also got the Bosch# 20876799 vacuum switch to turn it on and off, but I thought this would be a simple, 12v output to a relay to switch on and off when the vacuum pressure was out of range.
Turns out it is controlled by the PCM on cars like the VF commodore and E39a PCMs using a 5v reference, low reference and signal wire.
Assuming the switch output is 0-5v, is there any table I could utilise in the HPT SD OS that could send a 12v or ground signal to a relay to kick the pump on and then off when it reaches a certain voltage?
I'm already using EGR for my wideband, but was thinking possible the EVAP controls or something similar?
I'm just looking to find if there's a way I can do it without going and buying a $100 12v vacuum pressure switch.