[Blasirl]

I am getting since last october (a year ago) P0300 and just in the last few months U0100. I have put in a new battery, new neg. batt. cable, new coil pack, new intake manifold (cause of STUPID CHECK VALVE FAILURE/MISSING), new spark plugs (irridium/oem type not coppers gapped at .28 IIRC) New valve cover (PCM valve went out)and fuel injector cleaner and different gas. Car worked well a few months after valve cover and intake manifold replacement but now I still have p0300! and the crazy U0100. Any updates and help for me?

52300 Miles 2012 Cruze 1.4 liter turbo 1LT, Only mod is K&N air intake. also have 1000 watt rms amp but was not driving sub at the time of it coming on. Servive stabilitrak and traction control obviosly came on when it was sputtering missfiring. Misfires were very LIGHt and not rough at all.

I did a normal light drive when it happened first recently (after new parts added) and 2nd time was with a very light launch ( turn of Trac. Control , give gas and let off brake )

Plug your VIN in here to see if there are any recalls for your car: Recalls by VIN

The generic OBD trouble code U0100 is a serious situation where the signals between the electronic control module (ECM) or the powertrain control module (PCM) and a particular module have been lost. There could also be a problem with the CAN bus wiring disrupting communications.


A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

Read more at: https://www.obd-codes.com/p0300



As for the electrical, did you really inspect the positive cable as well? I would double check your gaps and reinspect your boots to make sure there are no rips or deformed areas.