VY V6 3.8L Series II
ECU: 16269238
Couldn't seem to figure out why not getting a good earth on the O2's.
Initially I saw 8ohms and 16ohms resistance on the O2 harnesses when testing. D3 (blu/bla) and D5 (gry/wh). D4 and C9 were fine.
O2 harness wires to C/D 32 pin connector are all good at 0.1 ohms.
Pins D3 and D5 can't get continuity to any other earth in the ecu or the frame of it. Is the ECU buggered? Or am I lost?
O2 earths not working at ecu
-
Alcyone
- Posts: 1
- Joined: Sun Oct 29, 2017 4:47 pm
- cars: VY V6
2007 Foz
1989 & 1991 Carb Powered Subies!
-
vlad01
- Posts: 8549
- Joined: Mon Oct 08, 2012 8:41 am
- cars: VP I S
VP I executive
VP II executive
VP II executive #2 - Location: Kyneton, Vic
Re: O2 earths not working at ecu
This is normal, all the delco PCMs and ECUs use an isolated virtual earth of sorts for their o2 sensors. I imagine that this allows the ADC, opamps or whatever to have their own independent and isolated circuits obtain a cleaner reading of the o2 sensors as the small voltages and wave form of them are very susceptible to noise and voltage offset from other external circuits and electrical environments.
When upgrading my VP to use the VT style heated o2, I made an adapter that supplied the heater power and heater ground, but left the actual sensor circuits as factory with it's own floating ground. Works great and readings are accurate when compared to the wideband when cross checking the readings.
When upgrading my VP to use the VT style heated o2, I made an adapter that supplied the heater power and heater ground, but left the actual sensor circuits as factory with it's own floating ground. Works great and readings are accurate when compared to the wideband when cross checking the readings.