The R19 Auto has a pressure switch on the side of the gearbox facing forward. This little unit can spring a slight leak internally and being under pressure gradually forces transmission fluid up the cable to the connector at the ECU and then finding its way into the internal curcuit board for the Autos control system. This is possible because the wiring is well made and well sealed off from the outside elements all the way to the ECU, a nice flexible pipeline for the fluid.. This causes all sorts of related and non related changing and fault code symptoms leading to the diagnosis of other components as the possible culprit. If you experiance strange Auto behavior then as a routine basic check inspect the plug at the ECU end for moist oil. Better still remove ECU and open it up to check for Auto transmission fluid. I have seen one half full of fluid due to this fault not being diagnosed in this case the switch was replaced more by luck than good diagnosis but the car still had faults as the fluid stiill sat in the ECU. The customer came to me out of frustration and a lot of money being spent on chasing "GHOST" problems. After cleaning the ECU out with a good electronic cleaner and making good all connectors the car was as good as gold. Luckily no damage to curcuits. If you cant afford a new pressure switch or the new one is ex Europe and a month away you can very very carefully slice and remove the outer sheath on the wiring at ECU end. This will allow the fluid to vent before it gets to the ECU. If your having funny shift and other assorted electrical faults make this a part of your check list