Dear forum members I need your most expert advice. My 2003 S base type 3.0 with 90,000 has started giving me a P0037 fault code – (oxygen sensor) heater condition. I have reset it twice and it came back on with the 2nd restart of the engine both times. In the past your experience, strength and hope have always came through in my time of need, so please share - THANKS

 

Codes PDF is free download from the stickies here.

Check wiring if you like but probably need to replace the sensor.

 

Sounds like you need a new O2 sensor?
If you want to be sure swap it to the other side and see if the error codes follows.

If it does then the sensor has the problem.
If it does NOT then you have a different problem.
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+1 replace the O2 sensor with a direct fit unit - don't buy the "universal fit" O2 sensor where you splice the old O2 harness - you'll thank me later...

 

That's a good point and I should have brought it up!!

We have had several people turn a simple O2 sensor replacement into a giant mess because of this. They are not hard to get but it seems that the S Type only wants the exact replacement.
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Yours is on the opposite (Right) side as the one I just mended:
https://www.jaguarforums.com/forum/s...mended-120413/


Means you've got the easier side. While it is true swapping them would confirm that it is the sensor and nothing else, I wouldn't bother with that if I were you. Firstly, you'll have to remove the Oil Filter to swap them. Then if it IS the sensor that's bad, now you've got the bad one on the left side, so you have to pull the oil filter again to renew it. The sensor is about $50; Don't know your mileage but if it is something else, you'll likely need the sensor sooner or later anyway...just don't hide it in the garage where you can't find it when you do!


HO2 Sensor heater control circuit


low resistance –


bank 1, downstream (1/2)


Causes:
HO2 Sensor 1/2 heater control circuit:


short circuit to ground


HO2 Sensor 1/2 heater failure

 

THANKS for all the help! You guys are the best! I think I’ll give aholbro1’s suggestion a try. Wouldn’t you know it though; I just changed the oil a week ago!!! I will keep you posted!