Reading prior threads on this topic, its clear this one can be very misleading on a 2002. I am writing down my whole thought process/checks here in case it helps someone in future, or in case someone can add more insight.
So my 2002 XKR has thrown the classic P1646 DTC, supercharger fuel pump #2 relay. No Restricted performance warning. No noticeable symptoms.
I pulled pump #2 relay and it then threw P1671 as well. I also tried replacing with a new relay, P1646 remained, P1671 went away again.

According to my VIN number ending A25138 my car should follow the DTC summaries for model year 2001, AJ27

The DTC summary for 2001 Model year ON lists P1646 as fuel pump 2 on supercharged cars.




And it does NOT CONTAIN a P1671 DTC AT ALL.


However, 2000 model year onwards does:

And it has P1646 as upstream O2 sensor.


My car was sold in the US in 2002, but its engine was manufactured Aug 1st 2001. I recall reading somewhere that the revision change to gen 3 metal tensioners was Aug 13th 2001. So I am thinking they made multiple changes at that time, and my car just missed them, and effectively my car is a 2000 model year when it comes to DTCs.

Based on:
When I pull the fuel pump 2 relay, I get the error code for fuel pump 2 relay for a 2000 XKR - P1671 - a DTC which shouldn't even exist on my car. This also invokes restricted performance, which matches the description of fuel pump 2 relay fault.
Both fuel pumps appear to be working (pulling the relays in turn and clicking on ignition, I hear them run in the trunk.
So next I am going to check the H02S heaters relay in the control module enclosure

So I am going to troubleshoot this as the 02 bank one upstream issue in the 2000 MY DTC guide, not as a fuel pump #2 relay per the 2001MY guide.

And this is a note to say - the VIN ranges indicated in JTIS appear to be wrong, I am using JTIS Version 1.3 from August 2002, and I've seen this same oddness in the DTC guides I've downloaded from this site too.

Never a dull moment with this car!

At least it had the common courtesy to only throw an O2 sensor fault on the drive BACK from the smog place, not to it. I imagine that would have been a failure.

 

Yes, for some reason Jaguar shuffled those codes around for MY2001. They seem to have reverted from 2002 on (I haven't ever found a MY2002-specific list). 2003 reports P1646 as HO2S again..

The 'Points of Interest' section of the attached Heritage document show that MY2002 introduction starts at VIN A24196, so yours is definitely a MY2002 car.

Unfortunately there are quite a few errors in JTIS.

 

Oooh, thank you! Handy document. And hey, errors or not, I'm just happy I'm not looking at removing the fuel tank...

 

I can't find (in the PDFs I have) P1671 for any XK8/XKR.

I suppose the car is MY (something, 2002 in this case) but the software may have been updated with new codes added. Ideally a new PDF would be released - or did they escape and so some could be missing?

The PDF(s) with the odd P1646 meaning may be a doc error, sadly.

Hopefully IDS/SDD would see whatever version the software (here, in the PCM) is and either ask to update it or know the DTCs relevant to that version.

 

Michael,

I recall that at least for some Jaguar models, the U.S. model years are one year newer than those for the U.K. For example, according to the Heritage Trust document you posted, my XKR would be a 2000 MY car, but it is registered in the U.S. as a 2001 model. I wonder if Throwback needs to take this into account when reviewing DTC Summaries, which may follow U.K. model years unless they are a North American edition...? I'll have to check some of the DTC Summaries in my collection to see if there's a note as to the market they were published for.

Cheers,

Don

 

Hey Don


Part of it is due to Jaguar's releasing of a new MY out of sync with the calendar year.

I guess that, similar to here, in the US a new car takes the year it was first registered, irrespective of when it was built or the manufacturer's definition?

It can work in reverse: I was recently asked a question about a locally-registered '2002' car. When I saw it, it was clearly a 4.2L MY2003.
Here, it's not possible to tell the year of a car from its registration as the J-numbers are re-used.

I expect that vehicle documentation is provided in the language of its intended market, but I'm not aware if this applies to technical stuff other than the JEPC.

The 2001 DTC list I have shows P3007 & P3008 for H02S issues but I can't find any reference to either on a forum search.

 

in the USA the manufacturer designates the model year on the MSO independent of the calendar year.(MSO = manufacturer’s statement of origin). The original selling dealer has an MSO that accompanies every car the manufacturer sends them. When they sell a car, they send the MSO directly to the state tag agent and the buyer takes his bill of sale receipt to the tag agent and buys his license tag. Sounds convoluted but in practice it’s really seamless.

But the tag agent always goes by the info on the MSO when issuing a title of ownership. Whatever year of manufacture it says is what goes on the title of ownership.

 

Z, thanks for the correction. That process seems logical enough.

I guess the MSO must record the MY rather than the manufactured date, since production ended in May 2005 even though there are some MY2006 models in the US.

Something doesn't add up in Don's example, though, with a VIN <A11051.

Still confused (although not too difficult these days ).

@Don - I wonder what code your XKR would throw if fuel pump relay #2 is pulled?

 

I was wrong last night - tired brain. I realize now that the Heritage Trust document shows calendar year breaks in the chart at the top, but model year breaks in the Points of Interest at the bottom. According to the Points of Interest, my XKR with VIN A15*** is indeed a MY 2001 according to the document. Sorry for my confusion!

Cheers,

Don

 

Phew! That's a relief. I'll sleep better tonight

Thanks, both. It all makes sense now - other than whatever happened to the 2001 DTC

 

Back in the 1960’s all the USA car manufacturers would bring out the new models at the first week in September. For example in Sept 1965 the new 1966 models would arrive, and be registered as 1966’s.

a notable exception to that scheduling would be the Ford Mustang which was introduced in April of 1964 at the New York Worlds Fair. Everyone called them a 1964.5 , and still do. But officially they were all titled as 1965 models.

but nowadays there is no coordination between manufacturers that I know of. And everyone introduces the new models in the fall at various times. But they are all still titled with the subsequent year officially

 

Thank you all; well, irrespective of being MY 2002, my car's DTC match up with a 2001 MY car. It seems the litmus test for this code, P1646, is pull out fuel pump relay #2 and see what happens - fuel pump relay fault P1646 on a 2002 XKR should come with restricted performance, and mine didn't, which led me to believe it is the O2 sensor. In any case, I've got 2 new wideband upstream denso sensors in hand now, and a whole weekend free to get them in there. Wish me luck getting the exhaust off and getting those sensors in.

 

Well, I got the sensor changed and it was a pig. got the harness unplugged, dropped the exhaust which was challenging (why so many slip joints... oh Jaguar, couldn't you cough up a couple extra quid for flanges?) Didn't want to unscrew for love nor money. Almost rounded it off.
Then I found this thread:
https://www.jaguarforums.com/forum/x...2/#post2708611
And learned of the secret way of doing this using the AC drain port as access for a big extension to get a breaker bar on the sensor.

The accursed sensor. A wobble socket is a vital tool for any DIY jaguar mechanic.

Exhausts off. In the end I removed the backboxes as well to allow me enough wiggle room to get the mid section disconnected from the cats.

this is provides a lot more leverage on the sensor than going up from under the car. I had to use more than 100 ft lbs of torque to get this sensor off. I gave myself a black eye trying to do this from underneath yesterday when the O2 socket slipped off the sensor and the ratchet landed on my face.

I now have a car with no MIL or DTCs

Still haven't put the exhaust back on though as I want to do the other side, which is even easier to access via the drivers footwell AC drain port. However, the left hand side O2 sensor connector plug is less easy to access to clip together so I will do that another day once I've done some more research. I am thinking removing the scuttle panel will make access to the harness connector much easier and I can do the HVAC filter at the same time. Or maybe I just crack it loose, cut the wire and pull the harness up from the top to get more purchase on the plug to unplug it, and plugging in the new connector should be easier than unplugging it.

I still want to give whoever decided to locate those connectors behind/under the throttle body and under the scuttle panel a good slap.

 

So, got the second sensor done. For the record if anyone is doing this, a good way to feed the wire for the left hand O2 sensor is to tie string to the old one, unscrew it, pull it up through the engine bay, then use the string the pull the new sensor back through the wire loom from the top at the back of the engine down to the cat, screw it in most of the way by hand, torque it through the AC drain hole then plug it in. I also tied string to the connector end when I fed it back through so you can fish the plug back out again once you are done screwing the sensor in.

Its also probably worth getting a very deep 22mm socket to remove the old sensors as the sensor tool I used had too much play in it and kinda rounded both sensors off, but it got them out, just.

RESOLVED.