Engine Codes! - 2007 SS/ SC Donor engine codes

[Grayson]

Codes:
P0123 - Pedal Position Sensor Circuit High (Throttle Body?)
P0107 - Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage
P0443 - EVAP Emission (EVAP) Purge Solenoid Valve Control Circuit
P0449 - EVAP Emission (EVAP) Vent Solenoid Valve Control Circuit
P0452 - Fuel Tank Pressure Sensor Circuit Low Voltage
P2229 - Barometric Pressure (BARO) Sensor Circuit High Voltage

Hey everyone, I am having some issues with a bunch of engine codes all of a sudden.
I just replaced my serpentine belt and now all of a sudden I have a bunch of codes and the car won't stay running after it starts and it runs really rich and rough when it does.

I think its the throttle body that is the issue that im having but my OBDII pulled all of the codes above. I think it might be both the throttle body and a ground issue but I want to see if anyone else has had this issue or has an idea on what these codes could indicate.

For the P0449 and P0443 codes I think I removed this from my car so that could explain these codes but could be something else.

I dont know why I have the P0107 or the P2229 codes and what they might mean.

It seems like there is a ground or voltage issue somewhere but it could be something else. If you have any ideas please let me know!

Donor: 2007 SS/SC

 

[Gtstorey]

All of a sudden after replacing the belt, do you mean first start?

 

[Ross]

A loose ground makes sense if all these codes arrived at the same time.

A P0123 code in a Chevy Cobalt indicates that the powertrain control module (PCM) has received a reading from the throttle position sensor (TPS) that is higher than 4.5 volts for more than two seconds. This could mean that the sensor has failed or has a short.

The throttle position sensor is the pedal position request to the PCM, which normally will be followed by a throttle body motor move.

 

[Grayson]

All of a sudden after replacing the belt, do you mean first start?

No it ran fine before this. We had a clunking noise that we thiught was knock but turned out to be an unblead clutch. After we bled that system it ran fine with no strange sounds until yesterday which all we did was replace the belt.

 

[Gtstorey]

If the issue showed up immediately after replacing the belt, you need to inspect the wiring harness and connectors in that area.

 

[Desert Sasqwatch]

Playing with the clutch bleeder/elbow - right next to the fuse box and ECM? I would start by wiggling wires in that area and check that your ground connections there are still intact.

 

[Grayson]

Playing with the clutch bleeder/elbow - right next to the fuse box and ECM? I would start by wiggling wires in that area and check that your ground connections there are still intact.

I did that and everything that should be connected seems to be. I even fully inspected the pcm and the plugs to them and it seems they work as well.
I will double check tomorrow and add pictures if I take any

 

[Grayson]

If the issue showed up immediately after replacing the belt, you need to inspect the wiring harness and connectors in that area.

Will do, I think everything is connected and in tact but Ill check tomorrow and see if anything stands out

 

[Grayson]

A loose ground makes sense if all these codes arrived at the same time.

A P0123 code in a Chevy Cobalt indicates that the powertrain control module (PCM) has received a reading from the throttle position sensor (TPS) that is higher than 4.5 volts for more than two seconds. This could mean that the sensor has failed or has a short.

The throttle position sensor is the pedal position request to the PCM, which normally will be followed by a throttle body motor move.

What grounds should I be checking? In the rear, front or all the gounds?

 

[Gtstorey]

At some point you will have to start the oem service manual diagnostic for the codes.

 

[Ross]

There is a ground post on the drivers side engine mount... near the clutch bleeder.
There is a bunch of ECM and fuse box wires right near that too.
It is so tight near the clutch bleeder, that I like to bleed it when the subframe and engine are still 4" below their final position in the frame.
I wash electrical connectors with electrical cleaner, as dirt seems to keep migrating into them.

 

[Grayson]

There is a ground post on the drivers side engine mount... near the clutch bleeder.
There is a bunch of ECM and fuse box wires right near that too.
It is so tight near the clutch bleeder, that I like to bleed it when the subframe and engine are still 4" below their final position in the frame.
I wash electrical connectors with electrical cleaner, as dirt seems to keep migrating into them.

So I'm realizing that I think the other end of that ground isn't attached anywhere... thats the one that connects to the trans bellhousing right? I don't think the other end of that is hooked up. Where on the frame does that attach???

 

[Grayson]

There is a ground post on the drivers side engine mount... near the clutch bleeder.
There is a bunch of ECM and fuse box wires right near that too.
It is so tight near the clutch bleeder, that I like to bleed it when the subframe and engine are still 4" below their final position in the frame.
I wash electrical connectors with electrical cleaner, as dirt seems to keep migrating into them.

Oh wait, I think I know which youre talking about if its on the engine mount. That should be connected. I have another wire that conncets to the belhousing bolt near the gas tank and clutch bleeder that isnt connected on one end. Do you know where that connects?

 

[Gtstorey]

All grounds need a clean metal return path to the negative post of the battery. It doesn't really matter where the various other grounds connect at the frame. It just needs a clean, paint removed surface on the frame to connect it to (since the negative terminal is connected to the frame).

 

[Grayson]

Ok, so just wanted to update everyone.
We switched checked all the ground and hooked up the one I thought was missing. Then cleared the codes and still had issues and all codes came back.
Next we switched the throttle body and still had the issues and codes.
Next, we Checked all the ground points, filed some material off and cleaned them. This didn't work either.
Last thing I tried was I unhooked the battery and unplugged all the connectors to the PCM, checked them and plugged them back in and re hooked up the battery.

This worked, car started with no codes. The idle was high because we switched the throttle body and it needs to go through the relearn procedure.

We shut the car off because one of the O2 sensors was leaking so I tightened it and restarted it and we got another couple of codes.
P0443 and P0449. These are for th EVAP Vent solenoid valve which I think I removed so that doesn't matter as much to me.
P0452 Fuel pressure sensor circuit low voltage - This doesn't bother me much either

the one that bothers me is the P2229 which is Barometric Pressure sensor circuit high voltage.

I don't think its the sensor, probably a ground or a wire is mixed up. I know the map sensor on the SC is the same size and shape plug as the Barro sensor. Is it possible I accidently switched these and the car still can run?

Open to any ideas

 

[Gtstorey]

I don't think you can mix them up without throwing a code for both. Assuming the DTC setting are still stock. But if you replaced the baro sensor, it's possible you have the wrong one. I'm not sure this would set a high voltage code though since the output voltage range would be the same for both sensors.

But it's probably a wiring issue. Service manual will walk you through the steps to check the wiring issue as well as tell you the exact conditions it will have to see to set the code. It's possible the voltage isn't actually out of range but it just expects different readings for certain conditions.

 

[Grayson]

I don't think you can mix them up without throwing a code for both. Assuming the DTC setting are still stock. But if you replaced the baro sensor, it's possible you have the wrong one. I'm not sure this would set a high voltage code though since the output voltage range would be the same for both sensors.

But it's probably a wiring issue. Service manual will walk you through the steps to check the wiring issue as well as tell you the exact conditions it will have to see to set the code. It's possible the voltage isn't actually out of range but it just expects different readings for certain conditions.

I have a Haynes repair manual but they don't seem to talk about codes. Where can I reference the service manual you are referring to? The DTC codes might have changed but I wouldn't know how to view that. I haven't replaced the Barro sensor yet just because it seems from others that replacing the sensor most of the time doesn't fix the issue. I can try that and see if it works

 

[Ross]

My build thread, post #1, has some electrical references, that have testing proceedures:

Manuals and diagrams:
manual for your goblin donor. downloadable 7-zip or WinRaR
AllDataDIY Login

 

[Gtstorey]

Haynes/Chilton/Clymer etc. shouldn't even be mentioned even the same sentence as an oem service manual.

 

[Grayson]

Haynes/Chilton/Clymer etc. shouldn't even be mentioned even the same sentence as an oem service manual.

Good to know! I didn't even know that OEM services manuals were accessible. Looks like I have some not so light reading ahead of me!