Trouble resetting codes . Help please.
 

I am just wondering if I am chasing my tail while trying to repair my x type. I have tried to reset the fault codes using my rac reader however it just comes back with a fault reset fail code. I have also tried disconnecting the battery and leaving the lights on for 10 mins with no success either. Wondering if there is a way to reset the codes without a reader or is it possible that the codes are reappearing instantly even before the iginition is started.
Any help welcome.

Lubino, you are going about resetting the codes correctly by disconnecting the battery. That should clear any code out of the computer. The only way that it would is if you have a second battery in the car from say something like a car alarm. But, if your headlights are out when you have the battery removed, then you should have killed power to the ECM.

With that being said, if the trouble condition is still present after clearing the codes, yes, they will pop right back up and cause the CEL light to relight. So, you may be fighting that too.

Maybe im missing something chris but obd2 fault codes are not in erasable memory so disconnecting battery for a yr wont reset codes, if your having an issue with resetting either theyre hard faults or, you reader is not capable.

Cheers Chris. Would I be correct in saying that I would expect the engine management lights to go off at some point and then come on again if the fault was still there. I am just not convinced that the codes are being removed as they just seem to be there instantly even before I start the ignition properly ( I just switched on the electrics to ss if the codes disappeared at first).

Ok the car appears to drive fine below the 3000rpm range. Acceleration etc appears to be about normal and the car is as smooth as I would expect it. Just wondering if the car could be ok but just needs to go through the series of checks before it can turn the engine light off. Any thoughts?

What 'secret' DTCs will not clear????????????????

Brutal suggests that maybe the DTC(s) is/are the 'HARD FAULT' and the reason is that the fault(s) is/are still present!!!!!!!!!!!!!!!

more info!!!

bob gauff

Brutal, I have cleared the check engine light from a vehicle many a time by simply disconnecting the battery and going from there. maybe the actual code is locked inside of the computer, but the light will clear. What I am getting from Lubino is that he is disconnecting the battery and as soon as he starts the car again, the check engine light comes right back on. So, that would indicate to me that the problem is something that is fixed inside of the car and is causing the light to come right back on.

Yup still can't clear the lights of the dash with removal of the battery. The car drives really well below 3000 rpm and just wondering if it takes a little time for the computer to go through it's faults check before it removes the code from the ecu.

Lubino, once a fault is triggered, it is written into the computer till something is done to erase it. Even though the fault light may be clear, the code is still inside the computer. hence why you may be seeing faults that are not related to what you are seeing now. But, if you clear all of the codes and then they come back, then those are the active codes that you are getting with your current problem.

Seems to be improving futher
 

X type is now driving as per normal. No limp home mode etc and sounds just as it should. I think this may pretty close to getting sorted.
I had put in some injector cleaner into the car as well just in case it may have all been triggered by injector problems.

and finally...with the help of so many of the board members... the dash is back to normal. Must have been that the car had to run through some cycles before clearing off the error codes.
thanks all

Hate to be the bearer of bad tidings, but I would expect your fault light to come back on.

You car will carry out drive cycles to optimise the engine operation and economy but this process should not result in the Engine Management Light illuminating (see Jaguar X Type green drive cycle for info on these .

You will see code 1000 or 1111 (or both) on your code reader, these can not be reset.

You didn't metion what the code was, If it is an engine or transmition fault (P code) it should not re appear (after being cleared) until the engine is started. Other system faults will occure at any time.

Disconnecting your battery will make no difference just means that you have to re-enter your radio code as punishment.