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Jaguar XF Ambient Temperature reads 80 Degree C!

4718 Views 29 Replies 7 Participants Last post by  BigCatBoy
Hi Guys, Newbie here so be gentle....

Wondered if anyone can help me out, have looked through the forum but can see any similar issue.
Last week I took my 2009 XF 3.0D for a Re-Map, the results ofwhich I am Very happy with especially the extra 5-7mpg!

Only problem was on way home my climate control was going abit crazy, then I noticed the outside temperature reading was 80 degree C! (yes C, it reads 168 in F)!
Spoke to the Map guy and he said "oh nothing I have done must coincidence, it will be the Temp Sensor away", :(

I tried disconnecting the battery to see if this would re-set it but no joy, so I purchased a new Sensor and fitted it last night - still 80 degree!
Only I don't think its the Sensor at all as yesterday when it was Frosty the reading was down to 68, so that makes me think it may some kind of Calibration Issue?
Map Man says all he did was to clear all fault codes to check for any problems before the mapping procedure, so I know he was connected to the electronics and I know the ECU had to be removed for the re-map but this should not have caused this problem.
Anyone have any ideas of cause and remedy please?
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I have the same engine as you and had it remapped and had no problems but it is odd that this come up after the map ?. Was it a well known mapping company with well written software.
Hi Maca4,
Just been back at Programmer tonight, He hooked it back up to laptop & Codereaders and finally accepted that it Was caused by the re-map! So Fault found, But not solved...:(
There were no new fault codes on engine listed so that's a slight bonus as well.
Well known company, well written software! I will not Name & Shame until this is sorted first...
He said that he had seen this problem once before a while back, and is either going to re-write software & if that fails will return to standard, :( Which I REALLY do not want as I've got used to the extra horses, but more importantly seeing 50+MPG :-D as compared to only around 40-43 before!!!
Decent Mapping companies at decent prices seem to be in short supply here in S.W. Scotland...Bit of a lucky dip!
Cheers, will update when sorted...
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I wouldn't get too excited about the mpg improvement until you verify by calulation. The remaps likely thrown out the accuracy of the onboard computer.
Hi Glenno,
Will keep that in mind, I am keeping a close eye on the miles/tank as i know what I usually average and will report back when i refill...but seems to be good just now.
TBH I see no difference in fuel consumption at all after the remap if anything I'm using more as I tend to drive abit faster and harder and I'm thinking of having it reversed as the novelty is Waring off.
TBH I see no difference in fuel consumption at all after the remap if anything I'm using more as I tend to drive abit faster and harder and I'm thinking of having it reversed as the novelty is Waring off.
Honestly Maca4?
I was a bit fed up with the poor MPG and thought a re-map would help improve it a bit while adding a few more horses at the same time.
I will need to wait until the new map is done then keep a close eye on it.
Previously I had a 1.6TDCI Focus to which I fitted a tuning box, it gave me an extra 25-30 BHP and when driving normally I could get around 10% more MPG (measured miles per tank and not going by dash read-out as the box adds additional fuel without the computer knowing). Was hoping a re-map to the XF would have the same result but doing a proper job rather than just over-fuelling with a tuning box.
Also interesting to hear Glenno say "The remaps likely thrown out the accuracy of the onboard computer." as I thought that a re-map would keep everything proper as it should be or |I would have saved myself a lot of trouble and just
bought a tuning box!
Either way still after 2 years I still love my Jag....Just wish it wasn't so thirsty...:-D
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You'll almost certainly get a few MPG more with a decent remap, if your driving style doesn't change, don't worry.
I think its more to do with my driving style TBH I drive much quicker because I have so much more power but I do worry that all this power is not good in the long run I didn't go for the eco remap so have 307bhp not the 274bhp eco option. Every time I drive it I say to myself "lets just go nice and easy" but after I do a few miles I can't help myself and end up using all the power that's why I was thinking of going back to stock I'm worried something might go bang.

I would say 40-43mpg is good going given the size of the car are we talking about M-way miles here ?. I'm getting about 42mpg for mainly A roads and about 46/48 M-ways
Cheers Robinus, good to hear.

Maca4, i would not worry about any extra strain on your engine as the "S" runs 275BHP standard anyway and from what I can make out these are pretty bullet proof...
As I said earlier had a box on my Focus gave additional 30% power and run it for over 50k miles with no problems...

Previously I was getting around 36-38 on A roads and around 42 on a long run.
Now get around 45 and 51 on a run, (according to trip meter) but will confirm when i fill up next week...🤔

Then i will play with the new found horses and see what she's really like..🙈
I used to have the same problem as you when i had my nice take it easy, ☺ then this little fella would appear 😈
:evil: That's the one you know his brother.

Yes I guess I was amazed just how much faster it was after the map it really does fly but just wonder how much extra strain that puts on the turbo's. I'm not driving like a teenager but it's hard not to drive at speed along the sweeping country roads near to where I live the car was made for them.
It's not the engine, rather the ancillaries. The intercooler is a known weak point.
Ok Guys, Update time.
The extra power was fantastic especially as it was delivered between 2-3K revs just where you need it for overtaking...:-D
The difference was far better than I expected for a 20% increase in power, it was like night and day!

I took it easy for a week just so I could see how much the MPG had improved and the trip computer would show 50-52 for a run and 44-48 on my daily commute, so well impressed. :-D
BUT I also noted that the fuel gauge was not agreeing with this so I decided to re-fill and do a proper check. Trip was showing average of 44.3 MPG for over 350 miles, so I duly filled up and done the calculations which turned out to be SHOCKING... 33.2 MPG.:shock: So by taking it easy I was now 10% WORSE of than my "normal driving" before the re-map!!!

It was at this point I had had enough, called my man and he said that company would re-do a New Map for me as they had "occasionally" had a problem with an XF.
I politely Declined his offer because if their software was screwing up my Temps and saying it was 80'C thus totally confusing my Climate Control, showing me a 50+ MPG when in fact it was over 10 less, then what else was being messed up that I did not know about?
In all Fairness the lad agreed with me and I had the Standard Map re-instated, with a Full Refund I might add, so not all bad, despite three 100 mile round trips! (1 for map, 1 for computer checks to see if that would fix problems, then 1 to return to normal state).

My only complaint now is my pride and joy now feels Sluggish with ONLY 237 BHP, but on the up-side I am now getting my usual 37MPG average...(though I much preferred seeing 50 mpg. :twisted:...)
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so was this a big remap company ?

I am not expecting you to name them as they have been pretty good returning it back to stock and money back but just wondered if it was one of the big players as mine was so have the remap written specifically for my car make and model.
so was this a big remap company ?

I am not expecting you to name them as they have been pretty good returning it back to stock and money back but just wondered if it was one of the big players as mine was so have the remap written specifically for my car make and model.
Hi Maca4,
It was a franchise agent for Regal Tuning in York...
The websites seemed spot on, they seemed to know what they were talking about etc, etc.
The agent was spot on, it actually cost him money because he only does the mapping. He pays a local garage to remove the ECU and he maps it.
So it was removed the 1st time to re-map and then the second time for it to be returned to Stock map, so he paid the garage twice while refunding me in Total...He was a top lad to be honest.
I suppose he can only use what Regal supply him with!
He said Regal told him they "Occasionally" have a problem with Jaguar 3.0D...
You know what they say, "if it seems too good to be true, then it usually is" and at £220 it was very cheap....:-D ..But I would still have thought it would work ok as they are bound to have done loads of these by now.
How much out of interest did yours cost, no point in saying where as it will be too far to travel for me...:cry:
I was also quoted £320, £350 and £395 by others in Central Scotland, but chose the one I did as closest to me as well as cheapest...
That many to choose from I suppose you pays yer money and takes yer chances.....
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Is your external remp reading fixed now then?
Is your external remp reading fixed now then?
Yep, Everything is back to normal...
Mine was done by Celtic @£299 they are based in Cornwall but cover the whole country as they have local approved agents.
Yes I bet it's really weird driving it back at factory spec isn't it, these remaps really do change the car don't they.
Yep, feels quite sluggish TBH.
Even though you know its not by any means.
Not sure on my next move, as this has put me off a bit, I was looking to boost MPG a little as i think 37 Av is petty poor. 😕
Will probably wait till Xmas is out of the eay then start my resesrch for a decent company...🤔
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