View Historic Error Codes

[Fraz]

Hello, first post so please be gentle

I purchased a 2019 v6 chequred flag coupe 3 months ago and been loving it! After years of boring diesels for work it has totally rekindled my enjoyment of driving.

However, last week, after a very short 1.5 mile trip to the supermarket, the yellow engine light came on, flashing, and the car started to run like a total dog, although no message on the dash to say it was in limp home mode or anything.

I was almost home so I parked up in my drive, let it sit for an hour, started it again and the light was gone and it was running ok.

However I feel like its maybe a bit flat, especially at low revs. It could be that I am paranoid after the light being on, but I am pretty sure its not quite 100%

I picked up a cheap obd2 reader in the hope I could see what the error code had been, but there is nothing showing.

Can the proper diagnostic tools see that previous code? Im hoping to see its just a sensor that I could swap out to put my mind at ease and hopefully get it back to 100%.

Thanks in advance!

[Kev]

Welcome to the forum

Generic OBD readers will only read the standard codes, not the manufacturer specific ones which also tend to have a two digit suffix to identify a very specific fault. Depending on the code, sometimes it takes a couple of drive cycles to clear before normal service is resumed and it’s deleted from ‘pending’, however, if it reoccurs then the MiL will be illuminated to indicate a permanent fault

As yours is MY19 then you’d need Pathfinder and a DOIP interface to read the Jaaaag codes. Cars pre-17 (I think) can be read using SDD which is available, er, on certain interweb based auction sites. Pathfinder isn’t so readily available but is out there. Apparently. So I’ve heard…

[Fraz]

Thanks Kev

There is an independent jaaaag place not far from me, they are mainly older cars, but will hopefully have the software for 2019 onwards so will go give them a try.

I just didnt know if it would show up a code even though the light has since gone off. Its been a week of engine light-free driving so probably gone from pending I guess.

[Fraz]

Update...

The following popped up in the historic codes:

P0262-1C - Cylinder 1 injector circuit high - Voltage out of range
P0274-1C - Cylinder 5 injector circuit high - Voltage out of range
P0300-00 - Random Misfire detected
P0301-00 - Cylinder 1 misfire detected
P0305-00 - Cylinder 5 misfire detected
P1315-00 - Persistent Misfire - Catalyst Damage

First Question - Any obvious/known issues that causes this?
Second Question - Is it just a one-off anomaly now that the light has gone off (on its own, not reset)
Third Question - As the light is off, my warranty wont cover anything, what, if any, potential additional damage could I be doing while driving it at the moment, waiting for it to fault again?
The independent went straight to "XK V8s are bad for the fuel pump disintegrating and taking out injectors, it could be that, which costs about £5000..." But they didn't seem that confident, they are very much more of a classic Jag workshop.

I hope this is nothing too crazy as really loving the car and don't want to fall out with it so soon over a massive bill

[jonm]

It seems very strange that 2 injectors would fail at exactly the same time, and then start working again at exactly the same time, this would lead me to think the injectors are not the issue. 1 and 5 are also on different fuel rails and banks. no indication of fuel pressure issues so not fuel pump issue or the common problem of injector sticking open and dumping fuel.
Intermittent electrical wiring issue maybe but each injector has it's own pair of wires back to the ECU, making the ECU it's self the only common point between these 2 injectors but ECU failures are unheard of. wonder if maybe wiring harness rubbed through somewhere and shorting out to ground and so far only rubbed through and affecting 2 wires?

[jonm]

Also consider possibility an electric glitch has caused the ECU to Mis-detect an issue with those injectors that does not exist and then shut them down while you were driving, Could be issue with weak battery not providing enough power or maybe some 3rd part electrical devices like dashcams etc. generating EM interference and confusing the ECUs self check routines.
If it were me I would be inspecting every milimeter of the wiring harness from the injectors to the ECU.

[Fraz]

Thanks Jon, much appreciated.

I don't have any additional electronic devices connected (can't remember if my phone was connected to the CarPlay at that point but I doubt it on such a short journey).

I checked the battery with a basic OBD2 reader and it is saying 12.6V

As I said, I could be paranoid and feeling something that's not there after knowing the light came on, but it just feels that little bit flat now

[Fraz]

Would crappy supermarket fuel have anything to do with it, maybe sticking in some super?

[jonm]

Low octane fuel could make it feel flat, would cause the ecu to retard the ignition timing,
It would not cause those fault codes however.

[Fraz]

True.

Hoping it was just the ECU having a moment and it doesnt come back. I will get a few tanks of super into it and see if it helps.

Thanks for taking the time to reply.