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Natalya · 08-09-2016, 07:48 PM

Well another way would be have a button activate a SPDT relay that switches the signal to the ECM from the VSS to come from the board when you press the button, but now you've added a relay and an extra ground wire and a power source for the relay.

If the microcontroller acts as a repeater of the VSS signal until you press a button, I think this lets you omit a wire from the VSS to the button, but now you've got a wire from the microcontroller to the button and back, so it's the same level of complexity. I don't know if one of these is capable of reproducing the exact VSS signal as the signal changes. Maybe by using the TXD and RXD pins it could do that fairly reliably. Then again, it doesn't really matter if the ECM gets a signal that's slightly off.

*EDIT*
I just read your post again, are you talking about like a smart version where there are no buttons, you just drive and it goes into AS for you?

08-09-2016, 07:48 PM	#48 (permalink)
Natalya Engine-Off-Coast Join Date: Apr 2016 Location: Atlanta Posts: 564 Red 2000 Insight (2017 through 2019) - '00 Honda Insight 5MT 90 day: 64.72 mpg (US) Red 2000 Lithium Insight (2020) - '00 Honda Insight LTO 90 day: 71.76 mpg (US) Thanks: 224 Thanked 309 Times in 177 Posts	Well another way would be have a button activate a SPDT relay that switches the signal to the ECM from the VSS to come from the board when you press the button, but now you've added a relay and an extra ground wire and a power source for the relay. If the microcontroller acts as a repeater of the VSS signal until you press a button, I think this lets you omit a wire from the VSS to the button, but now you've got a wire from the microcontroller to the button and back, so it's the same level of complexity. I don't know if one of these is capable of reproducing the exact VSS signal as the signal changes. Maybe by using the TXD and RXD pins it could do that fairly reliably. Then again, it doesn't really matter if the ECM gets a signal that's slightly off. EDIT I just read your post again, are you talking about like a smart version where there are no buttons, you just drive and it goes into AS for you? Last edited by Natalya; 08-09-2016 at 08:00 PM..