P2227 BARO Code Troubleshooting

[LBZ]

Following the steps from gm for a P0227 code. Does anyone know what the values are supposed to be as per the following tests? A pic of the altitude vs. barometric pressure table they make reference to would be helpful…..

“Turn ON the ignition, with the engine OFF.
Observe and record the BARO parameter with a scan tool.
Compare the barometric pressure (BARO) value to the range specified in the altitude vs. barometric pressure table. Refer to Altitude vs Barometric Pressure .
Is the BARO parameter within the range specified?
--
Go to Step 3
Go to Step 7

3
Observe and record the Boost Pressure Sensor parameter with a scan tool.
Compare the Boost Pressure Sensor value to the range specified in the altitude vs. barometric pressure table. Refer to Altitude vs Barometric Pressure .
Is the Boost Pressure Sensor parameter within the range specified?”

So far all we have determined is that the baro sensor itself is fine.

 

[DAVe3283]

You can look up the barometric pressure for your location online. At sea level it is usually 100-103 kPa, depending on weather. Here at 2500' it is usually 92-93 kPa.

The main thing is if the baro sensor and MAP sensor don't match within reason at key on engine off it knows one of them has failed. Sometimes it'll run the diag while stopped and idling too, at least on the LB7.

On my LB7 I have a 6 bar (600 kPa / 87 PSIa) MAP sensor with poor repeatability (±5 kPa) and it kept throwing the code. Ended up having to adjust the allowed error, but since your sensors are stock odds are one of them is failing.

It could possibly be a poor wiring connection somewhere, but I've seen my share of baro and MAP sensor failures, so I'd personally just replace whichever doesn't match your local barometric pressure at key on engine off.

If they both match, drive the truck and get it nice and hot under the hood. Check them again hot, I've had them only mess up when hot before too.

Sent from my FlashScan V2 using Tapatalk

 

[Ron Nielson]

Maybe a mistype of the code #??

ChevroletP0227

Chevrolet DTC P0227​

Make: Chevrolet
Code: P0227
Definition: Accelerator Pedal Position Sensor 3 Low Input
Description: Key on or engine running; and the PCM detected the APP-3 sensor voltage was less than 250 mv for 2 seconds. Note: The APP3 Sensor should read near 4.5v at idle speed.

Cause:

• APP3 signal circuit is shorted to chassis or sensor ground
• APP3 VREF circuit has a high resistance condition (low VREF)
• APP3 sensor is damaged or has failed
• PCM is damaged

Related Service Bulletins: View This Bulletin

 

[JoshH]

I'm guessing the code you're diagnosing is P2227. That step is just meant to verify your barometric pressure sensor is reading correctly. They also say you can compare it to a known good baro sensor on another vehicle. If you have an atmospheric pressure sensor or even a weather app, you can likely get close enough to verify if it is accurate. That code sets when baro and MAP differ by more than 20 kPa at idle RPM and low load (such as idling or coasting to a stop at low speeds). What do baro and MAP read with the key on and engine not running? What do they read at idle?

 

[LBZ]

Ya P2227
Baro and boost read the same engine off, baro reads like 12.7 which is bang on, changes as it should if you give it pressure or apply vacuum. Just hucks a cel for some reason.

 

[LBZ]

Is there anywhere I can go to enter the vin to find out what the stock os is supposed to be for this truck? My buddy feels something isn’t right and wants to try a stock tune in this thing.

 

[TheBac]

TIS

I tried it with my VIN, and it showed my 9044 OS.

 

[Ron Nielson]

Did you test the BARO circuit? https://www.duramaxforum.com/threads/p2227-code-will-not-clear.649809/

 

[LBZ]

Did you test the BARO circuit? https://www.duramaxforum.com/threads/p2227-code-will-not-clear.649809/

Yes. Didn’t come to a conclusive answer

 

[LBZ]

Buddy changed out the ecm. Didn’t fix it.
I haven’t got any more time to look into it and neither does he so I think he might take it to GM and let them take a stab at it. I’ll report back what they find if it goes there and they fix it.