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Discussion Starter #1 (Edited)
Hello all new here hopefully someone can help me figure this turd out. Do my issue is the randomly won't start it I left it sit overnight. It runs great when it does no check engine lights or anything like that I've had the car alittle over a year now and never had any major issues with it. So here's my issue now that it's winter when it gets below freezing the car won't start cranks over great but no fire Fuel pump does not prime. I tested the pump it does prime when I pull the relay and put it back in with the key turned to accessory. I just put a brand new battery in in today and a new crank sensor also replaced the ignition switch still no luck. When I bought the car it would not shift out of 1st the solenoids were bad to I replaced those and did a water pump and timing belt while I was at it. Never really had a problem with the car til now I scanned the codes and it has p1850 stored it will not clear but that shouldn't cause the car not to start. I also noticed that when trying to turn the car over sometimes I have to turn the key more then 1 time for the starter to engage I assume the starter is going bad still shouldn't affect the car from firing up. I'm at wits end I've dumped a ton of new parts spent alot of money on parts for it reading forums and trying to figure this thing out. I have a fuel pump relay coming which should be here this week but I doubt that will fix it. If any one can help point me in the right direction that would be great. If anyone needs more details please feel free to ask its may daily driver and my other car has 400whp and I don't wanna drive it in the winter. Is there any module under the dash that could cause an issue like this I feel that it only started doing this when I parked my car on a hill and water ran from under the dash so something must have gotten wet under there and when it freezes it shorts out.
 

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Discussion Starter #5
I did quite a bit of digging on the car in the last couple of days. I found the fuel pump relay was bad the pump now runs properly but I no longer have spark. I'm waiting on my crank and cam sensor to show up I noticed that I can shift the car out of park without pressing the brake which I feel is an issue. I am a mechanic for a living but when it comes to volkswagens it's like a whole other ball game. The only code I have to work with is p1850. I checked all the chassis grounds I could find and wiring off the ecu. I did notice someone replaced some wires on the main harness they did a good job besides leaving the old wiring behind. The wiring runs to alittle plug on the driver side fender where my intake runs down. Not sure what sensor it is. But at this point it seems like I don't have spark everything else seems to work as it should. If the new crank and cam sensor doesn't fix it I'm starting to think the ecu went bad.
 

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Since you have a scanner do you have the ability to read live data? Are you able to see if your sensors are showing engine RPMs?
 

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Discussion Starter #7
Tach doesn't seem to move when cranking tested for spark at the coil with a plug no luck I think my scanner can do live data I have to check but we are getting hit with snow atm so ill check when I can
 

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Discussion Starter #8
I ordered a cable from ecs tuning and downloaded vag com lite from their website as soon as the cable shows up ill figure out how to use it.
 

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Discussion Starter #9
Also installed a new ecu relay still no luck. So hopefully the cable I ordered for vagcom will help fix this b.s
 

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Hello all new here hopefully someone can help me figure this turd out. Do my issue is the randomly won't start it I left it sit overnight. It runs great when it does no check engine lights or anything like that I've had the car alittle over a year now and never had any major issues with it. So here's my issue now that it's winter when it gets below freezing the car won't start cranks over great but no fire Fuel pump does not prime. I tested the pump it does prime when I pull the relay and put it back in with the key turned to accessory. I just put a brand new battery in in today and a new crank sensor also replaced the ignition switch still no luck. When I bought the car it would not shift out of 1st the solenoids were bad to I replaced those and did a water pump and timing belt while I was at it. Never really had a problem with the car til now I scanned the codes and it has p1850 stored it will not clear but that shouldn't cause the car not to start. I also noticed that when trying to turn the car over sometimes I have to turn the key more then 1 time for the starter to engage I assume the starter is going bad still shouldn't affect the car from firing up. I'm at wits end I've dumped a ton of new parts spent alot of money on parts for it reading forums and trying to figure this thing out. I have a fuel pump relay coming which should be here this week but I doubt that will fix it. If any one can help point me in the right direction that would be great. If anyone needs more details please feel free to ask its may daily driver and my other car has 400whp and I don't wanna drive it in the winter. Is there any module under the dash that could cause an issue like this I feel that it only started doing this when I parked my car on a hill and water ran from under the dash so something must have gotten wet under there and when it freezes it shorts out.
Hello, I had kind of the same issue that you have on my 2007 FSI Passat, find the ignition fuse or relay. I found a blown fuse.
 

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Discussion Starter #11
I did go over the fuses but every fuse and relay is good it started yesterday for a few minutes then died again I scanned with vagcom vcds and there's no communication to the ecu.
 
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