Help with P228C Code
 

I have a 2015 Camaro LS with a stage 2 overkill P1SC supercharger kit. Prior to installing this kit, I was getting a P228C code occasionally after running on E85 for years, but now I'm getting it all the time. The supercharger kit has been on since September, but it wasn't until last month that this code now comes on about 10 times every 30 min which puts the car in limb mode.

What I've replaced:
-high pressure fuel pump
-car has a new ZL1 low pressure pump
-high pressure fuel sensor at the rail
-low pressure fuel sensor at the tank
-high pressure fuel pump cam follower

My wideband shows the car isn't running lean or rich when the code triggers so I don't think it's a real issue. I'm thinking some sensor is on its way out and is making the ECU think there's low fuel pressure.

Any ideas as to what the next best step is? My tuner Will doesn't think it's the tune.

It's annoying to have to keep clearing this code to get my car out of limp mode.

Are there any other sensors I'm missing?

Check the lobes on the camshaft for wear. If the lobes have unusual wear or are worn you would have to replace it. Make sure the follower that rides on the cam to push in the pump, is not damaged or sticking in the bore

Also from TSB PIP5209C

Recommendation/Instructions
Re-check the terminals at the ECM for fit and tension as well as the crimp to wire connection.

Terminals to inspect in the ECM are connector x2 terminals 3, 18, and 19 for the fuel rail pressure sensor.

Connector x3 terminals 16 and 32 for the high pressure fuel pump.

Note: As little as 2 Ω on either circuit can cause DTCs to set

If any concerns are found, replace the affected terminals and verify the vehicle is repaired.

Thanks for the recommendations. I recently opened my valve covers and all cams look almost new. I also forgot to mention I changed the cam follower while swapping the high pressure pump.

I'll take a close look at the ECM connectors as I did mess around with them when I installed Will's E85 kit.

Checked ecm terminals and everything looks good.

Found this about a lawsuit where excessive e85 use triggered p228c:
https://m.carcomplaints.com/news/202...ismissed.shtml

As an experiment I added 3 gallons of premium from shell after my tank got down below 1/4 and so far my issue is resolved...

I'll report back if it comes back.

Maybe I need to run a tank of premium every so often to prevent this issue. I've ran the car solely on e85 for a few years now.

So far so good. Drove it another 2 hours and no more p228C engine code.

This makes me wonder if there's a bit of water in the tank as I have worked on the fuel system several times and left the low pressure fuel line open for days at a time.

Added a bottle of Iso-Heet and topped off the tank with top tier premium gas from Shell to get some good detergents running through the fuel system to clean it up.

Going to run this tank then fill it back up with E85 and see if that stops the p228c code.

It was coming on every 5 min and now it doesn't come on at all. I'll report back for others to use as a reference if they get this issue with E85. As I said, I've run it for years with no issues up until recently. Of note, it's winter here in Denver and I park it in a garage.

I'm back to running E85 after running a tank of premium Shell fuel and a bottle of Iso-Heet through the engine and am no longer throwing codes. Not sure what caused this. This code was initially coming on once every week then eventually started happening every few min of driving. Idle seemed to be unstable and had difficulty starting, fuel mileage was down a bit. My best guess is water contamination. I noticed some car companies say to run gasoline every so often if you keep running E85 all the time. Don't understand the logic behind that, but maybe there's something to that.

The P228C is because the E85 you are using is too thin and watery. The pumps aren’t able to maintain the necessary pressure. Adding gasoline to thicken it up has always helped when I throw the code. Also, I have found particular brands that seem to be better than others when it comes to the viscosity. And lastly, I never use e85 in the winter.