So I have the error code for the front driverside (US) O2 sensor out or failing in my 2002 XJR. I’ve searched, and can’t seem to find anything totally definitive on the correct sensor to use. There seem to be two different sensors with different resistances that changed at some time during production.

I want a plug-and-play sensor, don’t want to cut wires, etc and risk it still throwing a code if it’s that sensitive to a few ohms resistance change.

Could someone please point me to the correct sensor for my application? I need to replace my AC compressor, dryer, and belts this coming weekend, so I’d like to do the O2 sensor at the same time.

Thanks for any help,

Mike

 

Hi beady,

It may help if you could post the exact Diagnostic Trouble Code (DTC) in case there are known causes other than a failing oxygen sensor.

If you determine that you definitely have a failing O2 sensor, you can look up Jaguar part numbers at jaguarclassicparts.com:

Jaguar XJ Series X308 parts | Jaguar Heritage Parts UK


You can then look up the best Jaguar dealer prices at either jaguarmerriamparts.com (Merriam, KS) or gaudinjaguarparts.com (Las Vegas, NV).


If your original sensors were made by Denso, you can look up the Denso part number at:

Find My Part | DENSO Auto Parts


If your original sensors were made by Bosch, you can look up the Bosch part number at:

https://www.boschautoparts.com/auto


With the Denso or Bosch part number you can search the web and discount auto parts sellers like Rock Auto and Parts Geek for the best price.

Cheers,

Don

 

P1647 and a pesky P0705 related to the dreaded “transmission fault”,”transmission overtemp” fault. I don’t think the P0705 is related, but please enlighten me if so. Randomly every few months I get the “your transmission is overheated and I will only smash in to Low and Reverse gears at full line pressure”. I have to cycle the ignition or start/D/R/P/OFF over and over to clear it. I’ve had it do it on the first cold start on a morning in the 20’s (and it almost always happens on the first cold start in the morning), so I’m 100% certain it is not an overheat issue. Fluid and filter have been changed.

Thanks for taking the time to post the O2 sensor links, that is more info than I found after a lot of searching (this and other sites) previously.

My VIN ends in F49385 so it looks like a ~$230 sensor from those two vendors you linked. I can find sensors from both Denso and Bosch in those links that claim to fit. This Bosch sensor from Amazon is only $74.88 (referenced PN from the Bosch site) ; any way to know if it will fit without trying to see if I can tell which manufacturer of sensor I have now? I’d rather not do the job twice by having to pull everything out to get to the upstream sensor just to read it, then reinstall and drive to work for a week while I wait for a part, then do it all again.

My Jag seems to run fine with the exception of a check engine light from the P1647. I just cleared it again, will see if it come back tomorrow on the way to work (it has previously each time I’ve cleared it).

Thanks again,

Mike

 

Mike,

The closest DTC Summaries manual I have is for the 2001 AJ27 (attached). Curiously, neither P1647 nor P0705 are listed.... P1647 was apparently omitted inadvertently at the break between pages 48 and 49.

The 2000 manual (also attached) does list P1647. The fault description states: "ECM HO2S control malfunction – B bank, upstream"

The possible causes for that code are:

HO2S heater failure
HO2S sensing circuit short circuit to ground or high voltage
HO2S sensing circuit open circuit
ECM failure

It would be worth examining the sensor's wiring harness for any worn or broken insulation that could allow a short. You can also test the heater for continuity and compare its DC resistance to those of the other sensors. At the link below you can download the Electrical Guide, which shows which wires connect to the sensor heaters:

http://www.jagrepair.com/images/Auto.../jagxj2002.pdf


The 2000 manual doesn't list P0705 either (nor do the '99 and '98 manuals). According to the generic OBDII definitions, this code represents a fault with the Transmission Range Sensor, which signals to the Transmission Control Module (TCM) the gear position of the transmission. It might be worth checking the rotary switch and electrical connector on the left side of the transmission for oil contamination, corrosion or looseness.

Cheers,

Don

 

I think your car has the mercedes transmission, which has an electrical connection into the gearbox that is prone to leaking oil. Simple fix to remove, clean and replace with new seal.
Member with more experience might have more info.

 

That sleeve is at the right front corner.

Mercedes has a "new and improved" version.

 

Plums and Fred60, I replaced the connector several years ago when it was leaking oil.

I think it may be the plate inside the trans, or the temp sensor itself acting up. From my research, you can’t replace the sensor as it is part of the valve body.

I am almost to the point where I am going to solder in 1K Ohm resistor to ground with a switch in the temperature sensor wire. That way when it acts up I can flip the switch and the ECU will see 1k Ohms and think all is good and go back to normal behavior. The only thing holding me back is that I haven’t researched the wire color or a good location (preferably dry) to put in the switch and resistor (information welcomed . At some point the car is going to drive me over the edge and force me to do it. The only way home from where I work is over one of several interstate bridges. I will **** off a LOT of people driving home at 30-40 mph at 3-4k rpms in low gear for a dozen miles when the “normal” speed is closer to 70.

The timing seems to be random and not tied to rainy weather or temperature.

Thanks,

Mike

 

Don, at 145K miles and for only ~$75 (if that is the correct O2 sensor) it seems like a no brainer to just swap the sensor rather then fuss with troubleshooting it. I assume it’s a heater failure since the car runs fine otherwise.

Thanks,

Mike