I have a 2015 Z1 that I had pulled out of winter storage a few days ago to have the oil changed and, on the way to the dealership, the Check Engine MIL came on. The tech at the dealership pulled DTC codes P0296 and P0298, ran diagnostics and came up with a faulty EVAP purge solenoid (not closing). Once replacing this, he reset the OBD and the problem is resolved. That said, when I look on-line for an explanation of the codes, I see that GM is appreciably protective.

So, all I can tell is that I had generic power train faults with the air/fuel system. All the sites that I reviewed showed the codes to reflect "Cylinder 12 Contribution/Balance Fault" (P0296) or "Engine Oil Over Temperature" (P0298), neither of which obviously represents the trouble. So, can anybody tell me what the real definitions of these two codes are? Thanks in advance!

 

A search for P-296 Chevy gives several entries for P2096 CHEVROLET - Post Catalyst Fuel Trim System Too Lean Bank 1

and a search for P0298 yields P2098 Post Catalyst Fuel Trim System Too Lean Bank 2

Possible causes

• Faulty Heated Oxygen Sensor
• Heated Oxygen Sensor harness is open or shorted
• Heated Oxygen Sensor circuit poor electrical connection
• Exhaust leaks
• Contaminated Heated Oxygen Sensor

Since these are generic codes, sometimes adding the vehicle make helps.

Internet search is your friend.

GL

Ron

 

The dealership tech gave you fake codes.

 

The definitions I gave in my original post were what I found for the exact values as written on the service order. I was a little suspect of the transposed numbers (P20xx) when I found these on the net. It made me wonder if the tech had written them incorrectly (P02xx vs P20xx) on the service order, especially as the internet definition was much more reasonable for P20xx and the listed codes were associated with both banks. While the P20xx values are not generic for EPA mandated codes, looking at the input associated with the possible causes, your response is reasonable. I think I'll give my dealership a call and see if they'll help clear the question. Thanks!

 

The actual codes should be:

DTC P219A

Fuel Trim Cylinder Balance Bank 1

DTC P219B

Fuel Trim Cylinder Balance Bank 2

 

Thanks for the further info on this. Following receipt of Ron's input today, I used the "Chevrolet" search nomenclature associated with each of the codes (rather than "Chevy" or "GM," which I'd used before) and came across an interesting photo in an article. The suggestion by the author was lame, but the picture of the DTC on his tool showed the P2096 code. If you're interested, here's the link: http://www.superchevy.com/how-to/add...096-and-p2098/

Because the dealer tech necessarily cleared the codes to confirm the fix, there's no way of knowing absolutely what he was seeing. Probably a mea culpa on this, overall. The fortunate thing is for a Check Engine MIL, he fixed it first-try by replacing something that hasn't shown itself in any of the probable causes I've seen. Perhaps due to his diagnostics run following the code checks. I did find that the purge solenoid failing is relatively common, for whatever that's worth.

To keep from finding myself in this pickle again, I went out and purchased an INNOVA 3100j+ tool that provides the code definition in the readout. In the future, should I have any troubles that are OBDII related, at least I can make myself literate going in. Lessons learned . . . . Cheers!

 

Except an evap fault and a fuel trim code are not even remotely related.

 

Purge valve stuck open sucking fuel vapors out of the canister certainly will affect fuel trim.

 

Certainly will and indeed did!! To avoid a future situation where I'm scrambling to be in the know, I just purchased an INNOVA 3100j+ reader, which will provide the code definitions and I can be ahead of the curve. Might be better units out there, but looks like this will do the job. Cheers