After clearing the error codes on my BMW320D with Torque app the dashboard MIL is still off. What a relief after all the work and investigation that I've carried out. However, the experience does raise many questions.
One of the most important question is the accuracy, or perhaps more accurately, the interpretation of the error codes. It didn't help that the P3263 code generated by the 'P'ower train ECU was very difficult to find documentation for as it appeared to be manufacturer specific. That is, a code created by BMW. Eventually, it was found to be indicating a MAF (mass air flow) metering problem. So the MAF meter was replaced at great expense without fixing the problem! Fortunately, a simple improvised BlueTack test on the EGR valve indicated it was this unit all along.
Much of the work and expense would have been avoided if more information was available on what the ECU is measuring and then calculating to raise an error. It undoubtedly is an air flow discrepancy but not a faulty MAF meter.It appears that it is an error generated by measuring an unexpected airflow value caused by the faulty EGR valve. So, lesson learnt. Don't take the codes so literally.
My overall feeling though is that the manufacturers may have adopted the open standards but only reluctantly.
