Hi Folks,

I have a 98 D1 that sends OBDII MAF values about 1000 times lower than the Ultragage expects so it thinks I am getting 1500 MPG, but others report that 96 D1s play nice with the UG and it can calculate MPG accurately. Tom suggested it may be an AEL thing with the later D1s. To be specific, my OBDII gets MAF values between .06 and .61 Grams / Second as read by both the UG and my Actron CP9580 code reader and the UG expects values between 0 and 655 according to UG support.

So I am here to ask if your D2s play nice with your UGs and if so what years? If they do, does anyone know if a later D2 ECM will work on a D1 with AEL? I would like to have an accurate MPG and DTE readout so I don't have to spend half an hour each time to slowly fill my tank so I can track MPG (another D1 AEL issue).

 

Works fine in D2, I had a 2003 and a 1999. There is no easy way to put the Bosch computer in place of the GEMS ECU. Maybe if enough people contact UG they will put an update into future models to allow for a MAF multiplier to fix the issue.

Also, has anyone tried the fuel calibration to see if that will correct the issue?

 

I had a number of exchanges with UG support and they concluded it was Land Rover's problem and that I needed to get an ECU update from LR - I emailed my closest dealer and never got an answer (although one of their service guys had been very helpful looking up my radio code previously)

I have tried to use the UG fuel calibration, but the UG says I haven't used enough fuel for it to be able to calibrate - sort of the UG catch 22. I doubt it could calibrate for a 1000x discrepancy anyway. I did ask UG support if there was a way to scale the MAF, but they just repeated the range it expected and said that was the OBDII standard.

I checked the UG web site and it still does not list any LR Discovery exceptions in their exceptions list - just the TD5 2.5l. I had suggested to the support guy that they needed to add one for the 98 D1 and his answer was that no one else had ever reported a problem for a Discovery. I don't know if the 97s have the same MAF problem, but 96s apparently do not and LR may have fixed this problem in D2s.

I re-opened my support ticket with UG today to see if they have any other suggestions besides it being LR's fault; at the very least thay should add the exception so other 98 D1 owners will know the limitations.

 

UG replied and implied that either I didn't know how to do the fuel calibration, or the Rover MAF values are "nonsensical", or the fuel calibration is set so low that it doesn't report enough fuel used to allow it to be re-calibrated and they repeated the calibration proceedure again (same as in their online user manual).

I replied that I again followed their proceedure, but before zeroing the MPG the UG reported "gallons used" as .31 in 600 miles of driving and after zeroing "gallons used" it would take another 2000 miles of driving before it thought one gallon was used and allow calibration.

UG replied, "I would suggest that you place the gauge in another vehicle, start the cal process. Once 1 gallon is reached. Switch it back to the 1st vehicle. Then set the gallons in step 10 from 1gal to 100gal. That should result in 1500mpg become 15MPG. Once this is accomplished repeat the fuel cal in the 1st vehicle."

I bet they still won't put a 98 D1 in their list of exceptions or remove MPG, gallons used, ect. from their list of gages that will work in a 98 Discovery with a build date of 10/1997 (they actually list gages for seven different 98 Discovery build dates) BTW, my UG is Version EM Plus V 1.2

I like this unit and the functions that work are very helpful, but I bought it in part for the handy MPG tracking to help sort out engine improvements and I wonder now if other vehicles have compatibility problems that UG does not list or admit.

 

They are probably correct, the GEMS computer is giving nonsensical data for the MAF, but since they know about it you'd think they'd either offer an option to adjust for it or fix the issue that won't let you calibrate until you've used a gallon of fuel.

Another thought the manual mentions something about entering the calibration manually, in case you've reset to factory defaults. Maybe you could put a number in there that would get you closer, so that you can run the good calibration later, without having to find another car.

I've got that same version and I plugged it into a VW tdi jetta I just bought and they numbers it generates aren't even close to what the vehicle calculates on it's own. The manual says that for diesel you HAVE to calibrate or the numbers will be off by up to 3x.

I'm also in Northwest Arkansas. What color is your D1?

 

First - Where in NW arkansas? I live near Garfield North of Rogers and my D1 is black.

Second - was your 99 D1 that worked with the UG a GEMS 4.0 engine? I just read a fellow's story of putting a 4.6 in his 98 D1 and he used the 4.0 ECM so there must be some interchangeability. Frankenrover - Swapping a Bosch D2 4.6 engine into a GEMS D1 Land Rover Discovery

Maybe I need a different (newer?) ECM.

I don't think the MAF values are nonsensical as they seem to vary with RPM but are just much lower than the OBDII standard.

I looked at the "manual" calibration entry method and you still have to enter gallons used until the calibration factor number at the bottom matches that of your previous calibration - and the UG still has to think that you've used at least one gallon to let you do it.

I moved the UG to my wife's 99 Dodge Caravan today and it was showing a slight change in gallons used, so I will drive it to take her to Poteau tomorrow and let it rack up some gallons. Before moving it and after zeroing the UG and driving a short distance in the Disco today it was showing no gallons used and 580 MPG so I'll try re-calibrating it to 580 times whatever gallons used it shows when I get to Poteau and then I'll try it back in the Disco. What I don't know is if I can then re-calibrate the re-calibration later to make it accurate for the Disco.

I tried emailing the Little Rock dealer to see if there is an ECM ungrade, but no response yet and when I call I keep getting "leave a message" messages at sales, parts, and service departments.

 

I'm in Centerton.

I didn't mean the values weren't useful, I just meant that they weren't accurate. It sounds like the engineers didn't seem to care about where the "decimal point" was and just made their fuel maps fit.

My 1999 was a D2, so it was Bosch stock. My D1 was a 1996 but I didn't own the UG at that time.

 

OK, Centerton. I pass through there now and then.

So...were all D2s Bosch ECMs rather than GEMS? Perhaps only the two years of Advanced Evap Loss GEMS had the MAF value problem then.

I was able to change MPG calibration on my UG using our Chrysler van to get the "gallons used" to 7. It then took an hour of holding the up button on the UG in calibration mode to run it up to 700 gallons one tenth at a time (I should have done it at one gallon or two gallons used instead of 7) to set a calibration number of 100. That made the gallons used by the van advance so fast that the miles to empty alarm kept going off, but also made it easy to rack up two gallons used at idle and then bump up the calibration to 1000.

1000 proved to be way too much when I put the UG back in the Disco so Playing around and lowering the calibration number to 300 gave an average MPG reading of 5 to 6 so I've since lowered it to 170 to see what that gives; I am shooting for a reading around 10 MPG which is what I've actually gotten over the last 500 miles and then I can use the regular full tank method to do a normal calibration adjustment. It remains to be seen if it will ever be accurate, but at least I learned that it is possible to achieve a large calibration number if you have the patience- too bad the fastest you can change it is one tenth of a gallon at a time, but then UG didn't expect you to be changing it hundreds of gallons at a time.

BTW, the UG said the van's average MPG was 19 to 20 over 270 miles of freeway and rural two lane while its trip computer said 23.6 MPG. That was before any calibration of the UG.