2007 MCS R56, N14: 80,000 miles No leaks Son drives it 10-15 miles a day to school and back New serpentine belt and water pump 12/3/2021 New timing chain (and deleted adaptations) 3/19/2022 Last week I had a 'no spark, no start' situation. Car lost power and died while driving. P163x error codes (voltage monitoring control module communication error) led me to look for an electrical problem. I tested all fuses and relays under the hood and in the cabin by the passenger's feet. I unplugged all cables to both fuse boxes to check for burns, breaks, or water and found nothing. I did drop voltage tests with a digital multimeter and ground/power tests with a light probe and no findings. After all this, I still couldn't find a fix. Still 'no spark, no start'. I did have compression and fuel this entire time. I'm posting a video of some of the noises I was hearing while doing my voltage drop tests and fuse/relay testing. The relay works.... it's the K6300 position that is causing the relay to click. After two days of letting it just sit there, I went back out and tried starting the car. It started right up. No more relay clicking like in the video. However, there is now no power steering. I started and stopped the car several times without issue. I've driven down the block and back 5 times and still no power steering. I have the Foxwell NT510 and used that to delete adaptations with no results. I also have no power steering fault codes or icons. I'm at end of job here and don't even know where to look next. What are your thoughts? Again, this video is from a couple of days ago and the K6300 port is no longer clicking like this. My only issue now is power steering. I post this video in case it lends itself to an underlying problem that I don't know how to diagnose. https://youtube.com/shorts/Izr4sl3q4zE
I update my post with more information. I've tested all relays and they are fine. The K6300 position on the fuse housing is what is causing the relay to click. I can put any relay in the same position and it will make the same clicking. I've checked the ports for power and ground and there are no indicators of any problems. However, the clicking is now gone and there is only a power steering issue. I added the video to see if it could help find an underlying problem that I just can't see.
PROBLEM FIXED.... for now. After reading more about the EPS controle module in the Bentley Service Manual, I decided to unplug the harness from the EPS control module and check for burning or water marks. Nothing. Frustrated, I plugged the wire harness back in and decided to try driving the car again. It started right up and drove like normal. Everything works. No more power steering problems. No more rapid relay clicking in the fuse box under the hood. Other than unplugging everything, checking fuses/relays, and checking voltage drops, I'm not really sure what ended up fixing the car... which is unfortunate because I fear my car is going to die in the middle of driving it again. I think I can now appreciate the phrase 'gremlin in my mini'. Thanks for your help.
It sounds like the harness plug might be suspect if all you did was reconnect the plug to the EPS Control module. The action might have been enough to clean off a small amount of oxidation..... Maybe unplug the harness again and clean the plug contacts with spray electrical contact cleaner and apply some dielectric grease before reattaching the plug to the module.....