Hi all,
Now before any one says anything i know there is a very similar post but it doesnt answer my question so Im posting my problem here...

I bought a 2.5 V6 X Type before Christmas from a trader. It was all fine bar this engine light, which only came on during the test drive, so they tested it then and then the engine management light came on - they had it tested then and there and it came up with the fault P1646 (Think thats right, my memory is rubbish lol!) Which of course is "oxygen sensor fault".

I was told that as part of the sale it would be fixed.
I came to pick the car up - light still on. Apparently they were awaiting the part.

1 week later, mid December, the part had finally turned up and they took my car in to do the job. I came back the next day - light still on! I took it away and a few days later they took it back from me again and changed the other banks sensors (they were really confused with the whole 2-bank upstream downstream thing which wasnt helping!) Anyway, came to pick it up - the light was finally off! I got in, started her up, drove 200metres down the road and it came on again! I turned around and went back. They tested again - same fault!

At this point I was driving down to Devon the next day to visit my parents for Christmas, so I had to leave it there and was promised they would fix it in the new year.

I finally got to get her to them Thursday after their electrician contracted swine flu (!?) I took her in with 90miles in the tank and gleaming from a full wax. They said she would be ready for Friday, she wasnt. Finally got a call today, problem still not solved!! On top of this, she was FILTHY like dirt splatter marks all up the wings, and only 11 miles left in the tank!!!! I was fuming cos I been working all the over time I can get to save for a house and i dont need my car still not being fixed when i paid over the odds to buy from a trader, and as much as i love cleaning my car, I dont need to be removing thick dirt from where someone else has got to drive my 80-odd paid for miles which should have been getting me to work tomorrow morning!!!! Im not made of money!!!

Rant over (seriously im in such a bad mood now!) has anyone else had this problem? They reckon they have changed ALL the sensors now, and still nothing fixed, so they want to drive my car 20 odd miles to a so called "specialist". I would really be so happy for any advice cos I do NOT want them driving my car again nor stealing all my fuel!!!

 

Here's the AllData diagnostic for P1646. Looking for a short. I don't like the last line that says"INSTALL a new PCM".

I : DTC P0131, P0132, P0133, P1646. RIGHT-HAND BANK HO2S



I1 : CHECK THE CONSTANT CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR OPEN CIRCUIT

1. Disconnect the HO2S electrical connector EN37.
2. Disconnect the PCM electrical connector, EN16.
3. Measure the resistance between EN16, pin 84 (P) and EN37, pin 4 (P). Is the resistance less than 5 ohms?

Yes Goto I2



No REPAIR the circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



I2 : CHECK THE CONSTANT CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR SHORT TO GROUND

1. Measure the resistance between EN16, pin 84 (P) and GROUND. Is the resistance less than 10,000 ohms?

Yes REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



No Goto I3



I3 : CHECK THE CONSTANT CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR SHORT TO BATTERY

1. Connect the PCM electrical connector EN16.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between EN37, pin 4 (P) and GROUND. Is the voltage greater than 5 volts?

Yes REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



No Goto I4



I4 : CHECK THE VARIABLE CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR OPEN CIRCUIT

1. Disconnect the PCM electrical connector, EN16.
2. Measure the resistance between EN16, pin 83 (Y) and EN37, pin 3 (Y). Is the resistance less than 5 ohms?

Yes Goto I5



No REPAIR the circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



I5 : CHECK THE VARIABLE CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR SHORT TO GROUND

1. Measure the resistance between EN16, pin 83 (Y) and GROUND. Is the resistance less than 10,000 ohms?

Yes REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



No Goto I6



I6 : CHECK THE VARIABLE CIRCUIT OF THE RIGHT-HAND BANK HO2S FOR SHORT TO BATTERY

1. Connect the PCM electrical connector EN16.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between EN37, pin 3 (Y) and GROUND. Is the voltage greater than 5 volts?

Yes REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.



No INSTALL a new HO2S. CLEAR the DTCs. TEST the system for normal operation. If the DTC is repeated, INSTALL a new PCM. Before replacing a PCM, contact Dealer technical support.

 

mohrd : thank you SO much for your reply! This will be very helpful for me, and I will let you know what happens with a post in this topic again. It seems like i have been banging my head on a brick wall so this will hopefully highlight what the actual problem is!

Must say, I dont like that last line either ... however it should be covered by the trader at the end of the day, if thats what is needed to get that EM light off and thats what they promised they would do before I even picked the car up ... and over 1 month into ownership we are no further forward lol!! :-S

thanks again

 

I had a similar problem. Turns out I had 2 failed sensors. The diagnostic codes showed P1646 and P1647. Faults on both upstream sensor heaters.
I checked this out by measuring the resistance across the black wires of the sensor plug. It should read about 2.5 ohms, but both mine read open circuit.
So after getting a quote from my local Jag dealer of £90 per sensor and at least £180 per sensor for labour, I decided to change them myself.
I paid £70 per sensor from eBay and bought 2 types of lambda sensor removal sockets for £12 each, as I'd read that the sensors were quite difficult to remove. This was not an understatement, but I did manage it.
I tried to remove the rear sensor (near the bulkhead) without removing the inlet manifold, but after an hour of trying I gave up and removed the manifold, which wasn't as difficult as I'd anticipated. I also took the opportunity to replace the spark plugs at the same time, they looked like they hadn't been changed before, even though the car had been regularly serviced at Jag dealers.
I used the following socket and spanner to get the rear one:


I managed to loosen the sensor from above, but there is very little room to move the spanner once you get the socket on the sensor. Replacement is fairly easy.

The front sensor was easiest to remove from underneath the car, putting the following socket configuration up behind the radiator and fans:


It was well worth the effort, saving me at least £250.

 

thanks for the info, I am quite beginner but want to repeat your job. I cant see the pictures so I cant get feeling about what you have done. can you please tell me
1-how I can find the place of gray socket sensor and black socket sensor
2- how did you reach to sensor? up the engine or down the engine?
3-what was the size and length of spanner to open it? did you used same socket?
---------------
Jaguar x-type v6 2002 manual petrol

 

Hey Jagx52,

I see no one responded to you post. The black and gray sensors are clipped onto the firewall (guess you guys call it the bulkhead) next to the brake master cylinder. Just unclip them from the holder. Not sure what a spanner is as I am from the U.S. I will look into the size of the socket for you if you still need this.

Thanks and good luck,
The Dr!

 

Jagx52 - so you have V6, 3 cylinders across the back (bulkhead side) and 3 cylinders across the front (radiator side)

The 3 across the back is called BANK1
The 3 across the front is called BANK2

You have 4 (2 per bank) O2 sensors also known as Oxygen or lambda sensors

Each bank has an upsptream and a downstream O2 sensor

Upstream is in the exhaust manifold up by then engine

Downstream is in the catalytic converter

The code 1646 refers to bank1 upstream - O2 sensor in the exhaust manifold at the back of the engine bay.

stand at the front of the car looking at the engine bay, look down past, to the right of the engine, you will see the exhaust manifold with a heat shield around one side of it, you will also see the O2 sensor passing through the heatshield and screwed into the exhaust manifold, you'll see the wire coming from the back of the sensor follow it and you'll see as Dr Dome says it is clipped on the bulkhead

I believe there are a few ways to get at it, some say from underneath, some from the left and some from the right, you will probably need to undo and move the heatshield out the way unless you can get a spanner down between the exhaust manifold and heatshield. I think from replacing O2 sensors on other cars the size of the spanner is a 22mm if I remember right, if not then it will be around that size.

I needed mine replacing and have read its quite difficult to replace that one and although I have dpne all my own repairs over the past 25 years on all my cars I couldnt be arsed to do this one so paid a garage to do it - even the mechanic said it was a bit of a pig to do - the sensor cost £106 + VAT plus an hour labour - It is very advisable to get an original OEM sensor which is made by DENSO, these are what Jaguar fit

 

Hi jagx52. Sorry for the delayed reply, I had trouble finding the photos. I've updated the photo links on my post. Here are a few more photo's
https://www.dropbox.com/s/f84s18gig1...4_16_12_15.jpg
https://www.dropbox.com/s/grt27d1p1f...2012.14.07.jpg
https://www.dropbox.com/s/mlvv7mez11...2012.14.16.jpg
https://www.dropbox.com/s/fern5nn6cz...2012.14.42.jpg
https://www.dropbox.com/s/f8oijun0gq...2012.14.31.jpg

 

hello where can we see the shapes of it

 

6 years late asking...