Hi

I got a check engine light so I scanned it with my tool Launch X431 pro and I need your advice on these faults.

My car is XJ V6 supercharged 2013

 

Never trust any code you get until it repeats at least once. It's surprising how many "Historical Codes" are in some cars.

So you need to erase all codes and drive the car until it sets a code. Then erase again and drive some more.
You really want the car to throw the code repeatedly so you can trace it down and make sure it's real.
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Thanks for the advice

However I'm getting the same code of P0173 and check engine light every 7 to 10 days, the other code is new to me.

I cleaned the MAP and cleared the errors, will update later.

 

Don't know as this code has not been reported?
But it's a problem on Bank 2 of the engine so it only is affecting half of the cylinders.
I "think" bank 2 is the passenger side of the engine.

Might need the dealer on this one?
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So I am going to take a stab at this, but take this with a grain of salt as I haven’t dug into the particulars to answer this question.

Both banks are being shown in open loop. Normally after your car has warmed up, you want them to go into closed loop. This means it’s using all the sensors (MAF/MAP/ O2/ coolant temp) to precisely control fuel trim. Open loop means your car is using default fuel trim values without complete sensor input.

Not sure under what condition your car was under when readings are shown, but a normally functioning car will go into closed loop after a few minutes when it’s warmed up. It will at also occasionally go open loop if you floor the accelerator or something similar.

Bank 2 appears to be failing a self-test necessary to go into closed loop. It could be one of several things. I would try to find out which test it is failing, it should be possible using your obdii scanner (can’t remember how though). My guess is your code comes back every 7-10 days because that is how long it takes for you to complete the drive cycle necessary to complete the self tests.

My guess would be a bank 2 heated oxygen sensor (either upstream or downstream) is bad. Perhaps the heating element isn’t bringing it up to temp. But I’m sure there are other possibilities. Hopefully that helps.

All the best.

 

Thanks for your support.

I will monitor the readings and try to analyse freeze data.

Updating soon on this.

 

Yes but if there are any problems with the O2 heaters there are specific codes for that.
So I would expect to see more codes than just this one?

But if you suspect an O2 sensor remember a great way to tell is to swap the O2 sensors from side to side and see of the code follows.
No cost but again if you can't DIY you will pay.

This a bit unusual so please post back if you get it repaired.
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There are set conditions necessary to go closed loop. You can look them up somewhere, can’t remember exactly where off the top of my head. It requires things like coolant temp to be up, o2 sensor values to be in a certain range, o2 sensor temps are correct (pretty sure temp failure doesn’t trigger O2 sensor code which was initially my thought), cat temp up, ...etc.

I agree,O2 sensors may not be your issue. I would check what the reason for the loop closing error is and then start there. For O2 sensors you should be able to check their voltages and temperatures by OBDii scanner and check if they are within desirable range. If they are, then they are not the issue.

Another thought is that your error code is bank specific. This makes it unlikely that a shared component is triggering the issue. So coolant temp sensor, MAFS, and MAPS seem less likely in my opinion.

All the best.

 

That's a very good point!
Anything that's shared is not likely your problem. So I would NOT be looking at the MAF.
But cleaning it should not be a problem if you want to.
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Great info guys, I will do the O2 swap tomorrow, but I should do all / downs/ ups ????

Please advise.

 

Do both of them if you want to be sure.
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Any update? When you cleared the codes, did both codes come back or just the bank 2 trim code?