OBD-11 Codes list for X308 AJ27

Hi. I have spent hours trying to find a list of OBD codes that are specific to a 1999 X308 AJJ27 ((Possibly AJ26)) (AJJ8)
Jaguar XJ from 1997-2003.

I saw previously you could donate and access which I am happy to do, but can not find the path to get there. Between the old version of the forum and the new there is a lost in translation factor I think.

I am having issue with thrown codes for O2 sensors HO2 sensors and given the price of the sensors, I would like to buy the correct ones.

I found a nice clear list in multiple locations around the internet for AJ27 2001 and up, but guessing the computer is different since the codes do not seem to match at all.
Also found for X-type, 2003 and up.

Aside for actually being able to find the codes int, here is the information for my specific issue.

P1646 P1646

From what I can figure out it is upstream sensors on Bank 1 (right hand side) and upstream HO2 sensor on Bank 2 Left hand side.

Can anyone verify if this is correct?

I feel your pain.
I think your car is an AJ27.

this thread may or maynot give you some clues

.pdf from when I worked at the dealer.

AJ27_ECM_2001.pdf (170.6 KB)
AJ27_EMS_OBDII.pdf (757.7 KB)

Thank you. It seems to be slightly different than the codes my 1999 gives. I think I have it sorted, and figured out I need two upstream heated O2 sensors.

Question: Do you know of any sensors that match for Jaguar that will work other than Bosch and Denso? There are many options, some easier to get and some much cheaper. I found one Denso, which I believe is the OEM, and am trying to source another one. Jaguar dealer wants $514. :slight_smile:

Thank you. Looking at one of your previous posts, it seems my 1999 4.0 N/A V8 is an AJ26. Guessing it has slightly different codes, hence the P1646 and P1647, which are probably both upstream O2 sensors.

I managed to source one, and am looking for another. Any help on finding cross matched or brands other than Denso that will work with the car’s computer appreciated.

I use DENSO O2 sensors. Never tried other brands.

1998 XJ8 = AJ26
1998 XJR = AJ26
1999 XJ8 = AJ27
1999 XJR = AJ26
2000 XJ8/XJR = AJ27
2001 XJ8/XJR = AJ27



Hi: Thank you for the feedback.

My codes are 1646 and P1647, so I am going with Bank 1 and Bank 2 upstream sensors.

Meaning I need two Denso 2349016 sensors.

Does that seem correct in your opinion?

Thanks again.

The bank 2 O2 upstream sensor heater failed on a customer 1999 XK8 and I used a Rock Auto Denso 2349016.

Cleared the DTC and sent the car on it’s way.

Thanks, I have ordered two. WIll post results once I get parts installed and codes cleared.