P80 1998 1999 2000 AWD Fuel gauge averaging (NO) or totalling(YES) ?

Post by **abscate** » 22 Sep 2022, 08:56

The Great Debate is settled by the wiring diagram

The two fuel level senders in the saddle tank senders are in fact wired in series and thus provide a single, total resistance to the CDM which imparts the fuel gauge to indicate total fuel.

See how 6/33L and 6/33R are series wired and feed into A4 and A5 on the CDM

Post by **scot850** » 22 Sep 2022, 10:25

That is correct, unless one or other level sensor or wiring is bad!

Neil.

befarrer · Post by **befarrer** » 23 Sep 2022, 19:57

That is correct. It also uses the left tank to keep the right tank full. The total resistance is the same as the FWD P80's, therefore each AWD sender is half of the FWD sender.

454cid · Post by **454cid** » 24 Sep 2022, 00:38

I wonder if this has anything to do with the 850OBD2 app having two fuel levels. They're not the same, one is usually higher. I've always assumed it had something to do with the fuel light, but I'm not really sire of that, as the difference changes. I've also noticed that neither goes as high as they used to, which makes me think my sender is starting to get wonky.

Maestrours · Post by **Maestrours** » 14 Sep 2023, 12:29

Hello,

Can someone please tell me what resistance correspond to what level ?
It seems that my fuel gauge is wrong (when empty it says aroynd 10 liters).
What should be the values at empty, half and full tank ?
Regards,
Cyril

Post by **abscate** » 30 May 2026, 04:36

PatternFlyer · Post by **PatternFlyer** » 30 May 2026, 13:40

Appears to be for FWD, but the dropbox link doesn't work.
viewtopic.php?t=61820

There was another thread that I saw showing the AWD fuel level resistances, but can't find it easily.

VolvoOwl98 · Post by **VolvoOwl98** » 30 May 2026, 15:49

Many thanks for this! I’ll be looking at this and comparing it to my current predicament with Saskia’s fuel gauge inaccuracies

PatternFlyer · Post by **PatternFlyer** » 02 Jun 2026, 16:19

Ok... I just measured the restance on the VAST pump that arrived.
When it's empty, it is 160 ohm. When it is full (float all the way up), I get as low as 4.5 ~ 5.8 at the connectors. So, it should be read in series if the fuel gauge is same on V70XC.

Post by **abscate** » 02 Jun 2026, 18:40

Totally in line with the 325 ohms reported on FWD fuel senders , as two awd senders in series would give 325 ohms