2009 Chevy Aveo U0001 Code

Hi Folks,

So.. I'm hoping for suggestions as to where in the systems to look for the fault. No, there are no other codes,. I'm hoping a description of the "history" will help you who know these systems zero in on what I need to focus upon. The car is not a beater, clean in and out. Roughly 150 k on it. Ran flawlessly.. until.. Last June, the car blew a heater hose at highway speed. Towed it home. I R&Red the head (shaved, new valve stem seals, gaskets, etc). Wouldn't start/run worth a dime. Over a period of weeks and months, different codes would come up, indicating different sensors were not functioning. Like a parade, one, then another, then another. I replaced both cam position sensors, crank position sensor, and coolant temp sensor. Last Fall it fired up nicely, and we drove it to family for Thanksgiving , 2 1/2 hour drive each way. No problems. After that, it then developed a "hard start", where it took a couple crank overs before the engine would fire. Then it was smooth as could be. Not trusting it, we only drove it sporadically until Christmas, when we again headed to family. On the way, after an hour on the road, "check Engine" light comes on as we pass the Chevy dealership. We pull in. 5 hours later, they say the exhaust cam position sensor was faulty. " Safe to drive home?" "Yes". Half way there, engine suddenly dies. Starts up. Smooth. Full power. 20 minutes later, as we are 2 miles from home, engine suddenly running rough. "Check Engine" light on. "Hold" light flashing. We barely get to the house. I run codes. The Exhaust cam position sensor (which dealer did not have in stock, so..) and U0001. I replace the Ex Cam Pos sensor. Won't start. Run codes. Only U0001.

I've looked at all the connections I can see. Everything is clean, no corrosion. With it's history of saying all those sensors were bad, one after another.. is it most likely the ECM itself is at fault? What are the odds each sensor was fine until.. With no other codes to give me direction as to what system is NOW unhappy, how do I narrow down the fault-finding. I'm not really handy with a meter, resistance checks, etc.

Any ideas?

Hi Tyler, although I don't have a specific answer to your problem I do have the code U0001 showing on up on my insurance companies obd gizmo which is in my obd port. This keeps track of my driving etc. to lower my premium at the end of a year. The check engine light does not come on very much. I bought the same car you have, USED. Oh joy. Other codes have shown up and after changing a few parts the U0001 remains but only sporadically. I understand there might be a place under the coolant bottle where a bunch of wires meet. When it gets warmer I may take the bottle off and clean those connections which may explain some of the problems I had.

Thank you. Our car still sits in front of the house. I still don't know where to look. Wife now gets a ride to work, and I hear comments about "the car" as she wishes it was functional.
Wires under the hot water bottle? I'll have to look.
Before the snow, forecast for Friday!
;O)

Thanks for the reply. Where are you? N.B.? I am Ont. Just got my car back, had a new coolant bottle put on it. I told them to check the wiring and they said it LOOKS o.k. The other codes with this car were P0700 and P0107. So far those 2 haven't shown up lately which made me think of the loose/corroded wires having something in common with the Can Bus Harness and those 2 codes. I had a shop one time tell me it could cost $700 to check the wiring. No thanks, the car is not worth it. Good luck.

Hi Tyler, the U0001 code has not showed up after the new coolant tank was put in. Have you had to top up coolant now and again? A while ago I replaced the MAP sensor which cleared one code, then a new thermostat ASSEMBLY because the PLASTIC part developed a leak there and finally the coolant tank. This was my 2nd tank as it was new 2 years ago but after pressure testing it was found to be cracked and it's possible the coolant ran down the wires and triggered the U0001.