Hi All. New here and this is my first post so apologies for getting anything wrong in advance.
As brief as I can Jan this year engine ceased and had replacement fitted, ( second hand 130K ).
Ever since then I keep getting "Reduced Performance" .
My very good and reliable garage mechanic has tried all kinds of remedies to no avail.
Even had the software checked.
On doing that The original engine was a euro 4, the replacement is a euro 3.
A small software change was applied but to no avail.
I absolutely love driving my old Jag but am at my wits end on what to do.
I rely would appreciate some advise.

 

I’m not familiar with such variants, but I wonder how much it matters. I’m not aware of anything on the engine that would even store such info. AFAIK, it’s all just sensors and actuators.

Do you still have the old engine? Worst case if this mismatch is even a problem, you could swap the offending external bits from the old engine to new.

What codes are you getting? Please post the actual 5 digit codes (such as P0171) versus the definition your scanner might display. Some scanners give inaccurate definitions for Jaguar-specific codes, and that can lead you down the wrong troubleshooting path.

In my overinflated opinion, following the codes should lead you to a fix. For all we know, the donor engine had some unaddressed issue. Post the codes and we can go from there. If the engine is going into limp mode, there should be some corresponding fault codes to explain why.

 

Which engine variant?
What MY car?

 

It's a 2005 2.7 V6 TT diesel.
Fusewire371, I'll add it to your signature, should show up the next time you post.

 

If you have an '05 TDv6 then they didn't make a lower Euro rated one than yours. They fitted a DPF from early '06 but it was the same engine & was carried over into the early XF 2.7's.

 

Finally got back to the forum. The codes you asked for was P0196 and P0199.
Since I first posted for help I am now getting "Wash fluid low", ABS fault, DSC not available.
Any Help or advice I would be eternally grateful

 

First top up your screen washer fluid! That thosuld sort that out.

P0196 and P0199 are both related to the ETO sensor. (oil temperature, level and quality sensor.) I think this is the oil level sensor in a 2.7D but I am not sure??

The ABS and DSC faults are probably not related to the engine fault codes and should have given you more codes. That said it is probably a wheel speed sensor that has failed. You will need the code and/or the Jaguar SDD software to find out what one.

Mellow

 

Interesting about the ETO codes. I wonder if that has something to do with the different engine variants, perhaps with the computer not happy because it is not seeing some sensor inputs? I’m off on a camping trip now with just a sliver of cell coverage, so now way to research this theory for the next few days.

For the ABS and DSC faults, consider the battery condition:


https://www.jaguarforums.com/forum/s-type-s-type-r-supercharged-v8-x200-15/scorecard-handbrake-cruise-control-dsc-faults-193787


Are you also getting a parking brake fault? The three faults together often points to a battery problem. Just the first two is more likely to be a wheel speed sensor. But if the battery is of unknown vintage, I’d be tempted to spring for a replacement anyway and see if that helps.

 

Hi Karl
Yes I'm getting the parking brake fault but what I don't understand is the fact I could get these with varying battery voltages?
Also the wash tank is full to the brim and I still get "Low washer fluid"?

 

The latter fault is likely separate.

The others could well be battery or power/ground issues.

 

Heck if I understand why. I work in electronics and I’ve given myself a brain cramp trying to understand why a tired battery can often cause those three faults. A new battery is not a guaranteed fix, but read through that post I linked and decide for yourself. Please note I’m not talking just about the battery’s state of charge, but also the overall condition (especially age).



You’ve got the classic symptoms of a marginal battery that others have experienced. You’ve got to think differently with this situation. Just because the battery has enough oomph to spin the starter, that doesn’t mean all is good. It used to be that way with older vehicles, but not so on a car loaded with lots of electronics. It seems certain computer modules just aren’t happy if available voltage drops below a certain level under the massive load of the starter. You’d think the designers would have anticipated this and made accommodations, but that doesn’t seem to be the case.



Once again, I don’t fully understand why. I’ve got some crackpot theories, and no way to prove them. However, the exact cause doesn’t really matter, as long as we can grasp that a new battery often clears up the problem.



Eventually I gave up trying to make sense of this apparent design flaw. It’s like trying to understand why socks fall down yet underwear rides up. Makes no sense, does it? Rather than whine about how a computer module should behave in a perfect world, I shifted gears to how to work around this shortcoming. I compiled that scorecard thread to document what others have experienced, and how a new battery was often the fix.

Call me Mr. Vegas, but it sounds like a new battery is worth the gamble for your car.

 

As I understand it, an old/failing battery put under (even short term) load sags (in voltage). In effect its Ah capacity is well below what it used to have.