05 Aveo - P0300 Random Misfire

[Skipm3]

I have the same issue. Installed an 07 motor into an 05 and now have a P0300 code and CEL flashing. Vacuum gauge is steady at 20" @ 2000 rpm's. Performed the Crankshaft relearn procedure 3 times with no success. Any help would be appreciated. Feel free to call me: 920-499-1975. My name is Josh

[Daox]

I called up the local garage. Their "drive ability guy" is on vacation atm. Looks like I'll get it in late next week or so. I'm almost out of ideas.

One thing I did remember though. When I reset the codes on the engine, it stays in closed loop for a little while. After a while it kicks back into open loop. I guess in open loop mode it must not be misfiring because it runs fine. I should redo my tests with the codes reset to see what happens.

[mwebb]

what is below is reposted from earlier in this thread
in a GEO G10 engine
see CMP CKP Sync
i believe now that in your engines there is a difference in the CKP CMP waveforms between the 2005 and 2007 engines

in red and blue , the simplest of the simple CKP CMP waveform s and their relationship - if there is a difference of deviation of the CKP waveform to the CMP waveform because the newer engine is mechanically different with a different set of teeth on the Crankshaft and or Camshaft
the waveforms will not match and
the ECM will have a conniption - if either of you can provide Enhanced GM DTCs there should be a hint there

================================================== =
the blinking CEL means
the ECM thinks you have a cat killing misfire , stop driving right now .

so
there should be a P030X DTC where X is the number of the misfiring cylinder .
try to get your car to someone with
a scan tool with
GM Enhanced software ,
i believe the scan tool you are using is not up to the challenge.

the other (unlikely) possibility may be
CKP CMP alignment or more likely in compatibility because the replacement engine has a different crankshaft or camshaft wheel / teeth set than the original engine .

IF hot intake vacuum is 20 to 21" then there is no Cam Crank misalignment error , what is your intake vacuum ?

[Daox]

I finally took the car to a local garage yesterday. They diagnosed it this morning. Apparently, it needs a crankshaft relearn procedure done on it. They borrowed a tool from another local shop, but couldn't get it to work. They suggested I take it to a dealer to take care of this.

[mwebb]

Originally Posted by Daox

I finally took the car to a local garage yesterday. They diagnosed it this morning. Apparently, it needs a crankshaft relearn procedure done on it. They borrowed a tool from another local shop, but couldn't get it to work. They suggested I take it to a dealer to take care of this.

the CKP relearn will not work if there is a problem with CKP CMP sync or
if the CKP waveform is not what the ECM expects to see

the dealer does not have "scopes" and most dealers do not have techs that know what to do with a scope anyway , although most dealers have at least one tech that is extremely fluent in "scan tool" .

IF CKP relearn does not work with OEM tooling , you need to scope it .
4 days later ....

[Daox]

I haven't taken it in to the dealer yet. I hope to do it this week.

[mwebb]

OBD-2 Vehicle Explorer Scan Tool Browser

this tool claims to have the ability to get to
ENHANCED data for the Aveo

if you just get the connector for your car , the price may be less than a trip to the dealer
and
you would still have the scan tool , which would also function as an ENHANCED scan tool for your Paseo.... with the basic connector


this is not a fly by night company , the proprietor seems to be a bit eccentric ... which is not necessarily to be seen as detrimental

[Daox]

Just an update here. I brought the car in to the dealer last night. They were told to do a crankshaft relearn procedure on the car. I got the call this morning and that seems to have done it.

[gone-ot]

...EUREKA...success for Doax!

...so, there *IS* faith to be had in todays' new-fangled, magic, computerized ECU reprogramming boxes at the dealerships (if they have people smart enough to know *how* to use them)? (ha,ha)

[05chevygitney]

Hey if you guys are still around, I brought my car to a deals to have them do a crank position variation relearn. They said they did it and I am still getting a p0300 code, car runs perfect, any input?