2001 Eng Fault codes

So I pulled the fuse for the 4 heaters in exhaust sensors. (Wanted to stop it doing fuel trim as a trial . one of 3 things it inhibits when it gets that code)

I was expecting 4 codes P01xx from memory from the jag technical document. Aj26
However the codes I got are:

P0031
0037
0051
0057

They do seam to be generic codes for the heater failure.

But how can I trust any future codes and why is the documentation wrong ?

Thanks you

Also when disconnecting the grey plugs for the upsteam sensors I get.

P1646
P1647

P1646 # HO2 Sensor Control Malfunction Bank 1 Upstream
P1647 JAGUAR Code - HO2 Sensor Control Malfunction Bank 2 Upstream

To answer my own question. The following link seams to apply to 2001 on models

http://jagrepair.com/images/AutoRepairPhotos/P20003.PDF

I see a few others on the internet have suffered the same problem.

The link you have is for the X202.(not X308)

X308 2001 to 2003 DTC guide is the same. (no changes to the cars)
AJ27_ECM_2001.pdf (170.6 KB)
When I worked at the dealer we got paper guides back then and instead of new guide for the 2002 and 2003 X308, we just got new cover pages for the 2001 guide.

I have a supercharged car. I thought these were AJ26? or were the 2001’s different ?

The problem is that if I disconnect at upstream oxygen sensor, I get a code P1646.

If I look it your link to AJ27 it states Fuel pump 2 (SC) relay malfunction
If I look in the S type document I linked you get the correct description.
If I look in the AJ26 GTR 2003 download it is not listed.

years ago I had a cam sensor code that was not listed in the AJ26 list.

There are similar problem on the internet where people with 2001 NA cars have codes P1646, it says Fuel Pump #2. but of course NA cars don’t have a 2nd fuel pump. (I recently bumped a thread like this)
however the oxygen sensor would be a more likely fault.

The 1998/1999 XJR are AJ26.
The 2000 to 2003 XJR are AJ27.