Hey! I have had a really weird problem with my 2005 525d e60 since i bought it couple months ago. I noticed that everytime i started the car, or even just had the ignition off for about 10 seconds. the cluster lost the time, and the driven distance, consumption etc would also reset. Also the light, and needles sometimes takes a couple of seconds to "come alive". And if i switch off the ignition, the needles just stay where they are, kinda like freezing wherever they are when the ignition is turned off.I at first though it was a battery problem, and replaced it with a new agm battery, which i registerd and coded to the car. But nothing changed. I then replaced the alternator, and tried several times to charge the battery just in case. Tried to measure for voltage drop when switching ignition on but does not seem like it drops. Even tried with IBS sensor unplugged.
Yesterday i retrofitted the whole cluster for a new used one from a lci car. I got this reset and coded before i plugged it in. But to my surprise, this cluster also behaves exactly the same. I have scanned the car with ISTA several times checking for fault codes. But ther are none. Only for washer jet heating, some bulbs etc. Honestly have no idea what else to check. What else could possibly cause this? Or what other things does the cluster communicate with? Have searched the whole internet for answers but have not found anyone with my type of problem. I will add a picture that shows how the needles will stay whenever i take the ignition off. and add link to video showing the "delay" when switching ignition on.