[daire1976]

I have had a similar saga, I bought the car in March, literally 3 days before lockdown, it was going great and 2 months in it developed the "incorrect grade exhaust fluid, 512 miles to no engine restarts", I took it to a reputable jaguar garage, jagtech in Stockton and they drained system and refilled with adblue before resetting, all was well for almost 3 months and on a trip to London it reappeared, I had to travel to London so drove remainder of way and drove home to northeast with literally 30miles left, managed to get jagtech to have a look but prior to bringing it in I removed the adblue injector and cleaned the crystalline build up, jagtech done me a favour as they were fully booked and plugged diagnostics in and reset, with a view to getting booked back in within a few weeks but now we are back in lockdown. They advised that jaguar are really vague with help regarding the issue and have advised a 4 stage check, 1, drain down and replace adblue, 2 software update, 3 injector check and replace if any crystallisation, 4 sensor replace . Typically the fault reappeared last week whilst returning from London again. As the garage couldn't fit me in for a week I have purchased a panasonic hard book with the full JLR sdd software and a mongoose device. Today after 4 hours I managed to fathom my way through the sdd system and reset the fault, it got me to perform a number of tests with the injector removed from the exhaust and tested the spray pattern, then the quantity of adblue over a few minutes and the injector done exactly as it should, there was absolutely no crystallisation of the injector head so this has me leaning toward it being a o2 sensor further back. The injector is performing as should, the adblue is less than 1600 mile old, so my next step is to work out how to perform some checks on rear o2 sensor, but at 130-180 for a diagnostic that even jaguar seem to be struggling to understand I think I will use the "reset method" for now until they can offer a guaranteed fix as I don't want to be paying for diagnostics every few months.