P1647

[DougX]

Hi All, I know this subject has been covered before, but I am still unclear as to what Oxygen Sensor is faulty on my 1999 Jaguar XJ8 3.2L V8.
First, when checking out oxygen sensors with Jaguar and SNG Barratts, my particular sensor appears to be part number LNE1684BB. They list these as 2 needed.
My diagnostic tool is reading "Heated Oxygen Sensor Control Unit, Bank 2 open/shorted"
Looking at some "You Tube" video's, although not a Jaguar, the car with this problem and a V8 engine has two upper sensors either side of the block.
If this is the case with the XJ8, how do I know which one is needed to be replaced?

[Andy P]

Hi DougX,
P1647 relates to the passenger side top O2 sensor.

DTC P1647

As you can see from the list of possible causes, sensor failure is listed last.
Might be worth checking the electrical connections if you have been working in that area.
You have the correct Part No LNE1684BB but you only need one if your only replacing one.

No1 LNE1684BB No2 LNE1682BC

Using OEM parts on these cars means no drama.
Carrying out a hard reset after fitting a part can help clear things up.
Hope that helps and all is going well with the refurbishment of the X308.
Take Care.
Andy

[DougX]

Thanks Andy, just to clarify, its just one oxygen sensor needed as show in the example?

[Andy P]

Yes that's right Doug,the drivers side O2 sensor will come up with a different code if that one fails, P1646 I think.
Good luck
Andy

[DougX]

Hi Andy,
Looked in the engine bay and can see the drivers side oxygen sensor quite clearly (bottom left hand corner of picture). However, can't see the passenger side sensor.

This is the drivers side top sensor.
Looking down from the top of the engine bay you will see what I can see.

Getting in closer you will see (hopefully) a heat shield which is above the passenger side exhaust pipe.

Do you know if the sensor is behind this heat shield as it seems a bugger of a job to get to it with all the pipes around it, or does one get to the oxygen sensor from under the car?
Further note: I can't see any cabling for the oxygen sensor in this area.

[Andy P]

Hi Doug,hope all is well.
Yes the O2 sensor on the passenger side is underneath the heat shield which makes it a bit awkward.
Here's a link to a good write up of the procedure with some good photo's from jaguarforums.com:
Second post in the thread cover's the passenger side.

https://www.jaguarforums.com/forum/xj-x ... nt-195018/

Hope that helps.
Take care.
Andy

[DougX]

Thanks Andy, now I know what I am up against. Looks as if it going to be a problem job. I have asked an independent Jaguar garage to quote me to do this job. If the climate was warmer I would attempt it myself but as I want to get it running right ASAP, I will get the garage to do it - if the price is reasonable.

[DougX]

They are quoting £60 to replace, with me supplying the part. No brainer!! They can have the trouble of getting it out!!!

[DougX]

The problem WAS the oxygen sensor as it has been replaced today and boy what a difference it has made. The car is more responsive than before. Denso Oxygen Sensor from e-bay = £55, fitting by independent Jaguar service centre = £60. Money worth spent for the enjoyment I am now having in my X308!

[DougX]

Maybe short lived? I now have code P0155 come up. I have also noticed that every time I reach a destination and turn off the engine, the fan comes on for about 5 mins then switches off. Are these two things related?

[DougX]

Found to be poor contacts. Cleaned and working fine now.

[Andy P]

Hi Doug,
Thanks for the update.
Glad it was an easy fix for you.
Take care.
Andy

[RichardSEL]

Found to be poor contacts. Cleaned and working fine now.

What poor contacts? (just in case that code comes up for others in future)

[DougX]

This was the plug contacts from the oxygen sensor to the wiring loom. They were very dirty. A dig around and electrical spray did the trick.