Recently did an oil change and spark plugs and filled the tank (regular gas with oct boost, i know dont shame me but prem is $2/L) was driving down the highway doing 120/kmh when randomly it died engine turned off but still had power. Pulled over as soon as i could and tried to start the vehicle back up but it would not start. Got it towed. It popped fuse 105 I believe in the engine bay. Replaced it and it started for a min but ran rough. Replaced the cam magnetized adjuster and pig tail cause the connector was broke. Re aligned the sensor and wouldn't start. Went through the electrical system with a fine tooth comb, found a few cracked wires in the engine bay, repaired those and cleaned the entire harness cleaned the connectors on all the pig tails including front and back sam modules. Fuel pump was intermittent so I took it out and tested it which it was fine. No power to fuse 57 (fuel pump) not sure what module to go off of. The ecu, sam or central gateway. Was thinking the cgw as the fans would randomly kick on high and the sunroof started to act up. Still can't get vehicle started. Both batteries were good also put to Batts in key fob. Would appreciate any help or direction.


!!!!!ATTENTION!!!!
Opened ecu to check if a anything physically happened but didn't see anything. Also took part front sam and eis and did the Same thing but could not find anything just havent checked the cgw​​​​​ also replaced 2 cam position sensors with pig tail and crank sense. Still has code p0335

 

Is the alternator giving you about 14.4V? Is the AC voltage on the alternator output near zero? Hard to test if it won't run. When you have electrical issues, always establish a good baseline.

Check for water damage on rear SAM.

 

FYI the M273 motor adapts to regular gas just fine. If you have a more advanced scan tool you can set the gas type in the ECU variant coding. I run premium because I don't drive all that much and am fighting intake valve carbon, but I am seeing no mileage or performance benefit whatsoever.

 

What sort of plugs did you put in it.

 

Haven't got around to pulling the alt and doing a bench test yet.I was using my buddies snap-on scanner and ended up changing the fuel type to regular but that's good to know! I also put double platinum ngk plugs in if for now, noticed the valve cover tube seals needed to be done but haven't done them yet as it was running fine before hand. As for the rear sam, didn't seem to have moisture in or around its all though it wasn't damp in then spare tire department below the spare. But ill check it out again.

 

If your car didn’t do this before you changed your plugs it’s usually the simple things like some connector having come off or broken; or fouled plugs because they are a wrong heat range or something related to what you did.

In the alternative that something else was failing and the plugs have nothing to do with this I think you’ve done your due diligence with the other pieces that are suspect. In any case rule the heat range out.

There is no need to pull the alternator nor to do a bench test. Just put the car in maintenance mode on the voltage output will be right on your dash display. Do you want to get really froggy and do a load test you’ll need a MB star tool to run a diagnostics of the alternator with varying loads.

 

I personally don't think it would be the spark plugs or anything as the sun roof feel pump and fan all started acting up as soon as this issue happened.