I know this has to have been covered ad nauseum in other threads, but after extensive searching here and on the Internets at large, I can’t seem to find an answer.

I’m pretty positive in my last 2 D2s I was able to get a pretty consistent reading for Instant Fuel Economy, and as such was able to get pretty accurate Average Fuel Economy. Over time with the last 2 D2s I did the calibration process for fuel level and such and was able to continually refine it to be darn accurate.

My issue on my latest D2 is that the Instant Economy cycles from what is a pretty accurate reading to 0.00 more often than not. As such, the Average Economy is way off- to order of showing 5-7 mpg. Every tank I calculate manually and get 10-16. (The 10 has been due to A LOT of idling with recent weather and using the Disco as a farm vehicle in transporting stuff to horses) I’m running a Voyager rack and 265 75 16 tires. Prior to the rack and OEM size tires I was getting consistent 15-17, so I’ve expected it to drop, but we all know that dance.

Anyway, the only thing I can conclude is I’ve not done a setting properly and I can’t figure out what I’ve messed up. No codes other than P0501 (which may be related as the Nanocom shows it to be P1884, which in my research may be influencing things). I’ve done the calibration process for distance and I think done the calibration for MPG, but may have not- I can’t recall with all the other stuff I’ve been sorting out. I’m using MAF as the MPG unit of measure and am pretty positive I did it that way on the last 2.

This is my main page to give an idea of what I’m looking at:



For reference from the last D2:



I’ve changed the polling rate and run through most settings but can’t seem to get it. As I previously had a MAF code and some intake leaks I’ve sorted out, I thought it was due to that stuff, but I don’t think so any longer. Could it just be I’ve forgotten to do the MPG calculation? All that really entails is just filling up, driving, and filling up, and noting the correct amount of fuel that was put in. As the Instant Economy does show up- just intermittently- I thought this had to do with some polling rate.

I’m kinda baffled. Any ideas?

 

Oh yeah, I did realize one thing I’ve not adjusted correctly and just realized because I did before. For some reason I kept reading the fuel tank was 24.6 gallons, yet the Rave (per section 09-1) says it is 25.5. I can’t recall why I thought it was 24.6 or read that somewhere, but I do need to make that change. But again, I don’t think that will impact Instant Fuel Economy.

 

0.00 mpg is accurate when idling at a standstill, as you are burning fuel but not going anywhere. I have mine set to ltr/100km and it reads 999.9 as that’s the highest it can read.

 

Oh yeah, as I have thought this relevant, here is what I have seen regarding that code (P0501):

- The P0501 is the code that shows up on the UG. It does trigger the CEL after a few drive cycles once I clear it

- However, the Nanocom shows up as P1884 in the transmission section. I can’t recall (I’ll report back in a bit) which subset it is from the Nanocom, but here is the table I used on the Rave for it, so I’m pretty sure the 2 codes are related. The UG does not show P1884 (probably a generic vs Land Rover specific code or the like as a reason, but somewhat superfluous it seems)



I’m honing in on the ones with an asterisk as those are the ones that are considered emissions related and as such trigger the CEL. Again, I’ll report back as to the sub set reason and go from there.

And I have to be honest, my initial question may in fact end up solving my P0501 code (per the UG) as the more I think about it, the more this might be the source. But as always, my goal is not only to solve this for my machine, but to add to the collective since I’d have long ago given up on D2s if not for this forum.

 

Absolutely. However, mine is reading 0.00 on a regular- if not interval based- basis while in motion. Thus my confusion.

 

I guess if 1884 (20) Road Speed Invalid occurs, then the UG reads 0.00, because it uses road speed in the calculation.

 

EXACTLY my thoughts!!! So then, to validate what you are saying, I just went out and captured this:



That was in the transmission section, and this was under the Motronic section:



So then, this brings me full circle to the P0501. Based on my research (that I’ve posted a few times) it is a discrepancy from the VSS to what the WSSs are presenting. Per 18-2-55 in the Rave:



As such, is this my VSS? In the past I’ve been pointed to the WSSs and I would think this would cause the Amigos to turn on. However, I’ve replaced both front hubs and WSSs and never have had a code for the rears. And based on the above, I keep leaning to either the VSS, or the wiring to it. Again with the above, it doesn’t point to a wiring issue as then the code would be P0500.

 

Taking the above further, I found where the VSS is and it’s a mild PITA to get to as it’s above the valve body in the transmission. I forgot to pull the valve body when I did a transmission service last summer to take a look, but could this be it?

I’ve asked Tom at GBR about it and a local guru up in Dumbver and both are a bit stumped as well.

 

Sounds like the VSS to me, but I'm new to all this.