Next step. What to check?

[Batmonkey]

These are the codes 'getting. I checked all my grounds and they seem to be solid, but i wonder if I am missing a ground? All these are near the same area.

1. P0122 - Throttle Position Sensor/Switch A Circuit Low Input: This indicates an issue with the throttle position sensor (TPS) circuit where the voltage is lower than expected.
2. P0223 - Throttle/Pedal Position Sensor/Switch B Circuit High Input: This indicates a problem with the throttle position sensor (TPS) circuit where the voltage is higher than expected.
3. P0010 - "A" Camshaft Position Actuator Circuit/Open (Bank 1): This code indicates a problem with the variable valve timing (VVT) system's actuator circuit for the intake camshaft on bank 1.
4. P0013 - "B" Camshaft Position Actuator Circuit/Open (Bank 1): Similar to P0010, this code indicates a problem with the variable valve timing (VVT) system's actuator circuit, but for the exhaust camshaft on bank 1.
5. P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low Input: This code indicates an issue with the manifold absolute pressure (MAP) sensor circuit where the voltage is lower than expected.

Car won't start.

If I am missing a ground, where could I add one? I am not quite sure my next step on what to check. The P0122 and p0223 come back immediately as soon as i clear the codes without engine being cranked. DF did my wiring wiring harness. (chat gpt generated the descriptions for those does)

 

[Gtstorey]

Look up the oem diagnostic steps for the codes in am oem service manual and see if that gets you anywhere. Or review the wiring diagrams and see if those circuits share anything that might be missing.

This could always be individual wiring issues for each "circuit" or sensor.

Some history of where you are in your build will help.

 

[Batmonkey]

My build is done, just have to sort these electrical issues. The cobalt worked fine.

My next step that I know of is to that review the wiring diagrams and see what what they share in common. I did a lot of testing individual sensors last summer. I checked 5 volt reference for TPS and seemed okay, I put another one on from the wreckers, no change.

 

[ah.b.normal]

I'm NOT the electrical guy but it seems to me that any item that is a potenteometer(Brake light and clutch switch) or responds to a potenteometer(throttle body?), when replaced, a computer(BCM? ECM?) must be accessed and programed to recognize this devices' new parameters. Tech4? programmer? I hope this helps. If this IS the case please let me and the forum know, that is good info to know! Maybe there is a list somewhere that shows what all falls in to this "reprogram" category?

 

[Batmonkey]

I'm NOT the electrical guy but it seems to me that any item that is a potenteometer(Brake light and clutch switch) or responds to a potenteometer(throttle body?), when replaced, a computer(BCM? ECM?) must be accessed and programed to recognize this devices' new parameters. Tech4? programmer? I hope this helps. If this IS the case please let me and the forum know, that is good info to know! Maybe there is a list somewhere that shows what all falls in to this "reprogram" category?

that's actually something I was wondering if something needs to be reprogrammed

 

[Gtstorey]

I don't think those codes would indicate the need for a relearn. They would appear to be wiring codes. But I don't know where you pulled your descriptions from. You have to be careful if those are internet or code reader descriptions. It really should be confirmed to the service manual on what exactly it means and the conditions that are being tested and failing.

You could always concentrate on the MAP code since there isn't typically a relearn for it.

 

[Robinjo]

Do you get lights on and all that? Does the throttle body do anything with key switched on?

 

[Batmonkey]

Do you get lights on and all that? Does the throttle body do anything with key switched on?

Yes, eng power reduced, low fuel says. Engine cranks but wont start. Was gonna try and go after throttle position sensor because those codes come back without engine being started. Might try and after MAP code though.

 

[Desert Sasqwatch]

Listen to what @Gtstorey is directing you to look at first. Changing out sensors and switches before making certain your wiring is 100% is just spinning your tires in the mud. Electrical troubleshooting requires a methodical process to eliminate things in order. Replacing items haphazardly will mostly waste time and money - unless you get real lucky.

 

[Robinjo]

I had something similar, except mine would fire. I was getting code P2138. The solution was to rerun the wires from the APP (Accelerator Pedal) to the PCM C1 wires. I tried a new APP and Throttle Body unit as well since my code kept jumping around. This thread even goes through how to check the APP unit to make sure it's ok.

With the low fuel, are you really on a low fuel condition or is that a 'suspect' code. If suspect, that would lead me to think the fuel pump wiring might be wonky. Have you checked to see if there is fuel coming out if the hose is not connected?

On the LSJ, the fuel injector harness engine plug and MAF sensor plug were identical and can be mixed up (ask me how I know). Is this a possibility on the 2.2 variants?

P2138 code and intermittent limp mode!

Hey guys my goblin has the 2008 LNF ss doner. recently when I have been driving around, my goblin has been intermittently going into limp mode. It can be a 2 min drive or a 15 min drive when it kicks in. I turn on the car and turn it back on, then it’s fine again for another 2min-15min. It’s...

dfkitcar.com

 

[Joebob]

I will second or third that it is most likely NOT any of the sensors but bad wiring, grounds, and or plugs. I am also in the above thread and I also replaced all wiring between the pedal and the ECU including the plug, and have been stable ever since. MAF, TB, and pedal sit on the shelf.

You can check an engine ground that bolts near the oil filter, below the fuel rail. it can corrode and loose reliable continuity. Also make sure you add an extra ground between the frame lug under the fuse box to the engine block or tranny.

Joe

 

[Batmonkey]

I don't think those codes would indicate the need for a relearn. They would appear to be wiring codes. But I don't know where you pulled your descriptions from. You have to be careful if those are internet or code reader descriptions. It really should be confirmed to the service manual on what exactly it means and the conditions that are being tested and failing.

You could always concentrate on the MAP code since there isn't typically a relearn for it.

Fixed my map sensor. Cleared code and it Hasnt come back yet. Looked like a connector issue there. So that is solved for now.

Now working on my Throttle Body. I tested the connector on the throttle body it has 5 volt reference. But the Low Reference is not reading. I tested for continuity from ECM pin to the connector no readings. I also tested from battery positive to Low reference and no readings. So for now I am going to trace the wire from the connector back to the ECM. Have to undo a decent amount of wiring.

 

[Gtstorey]

Always the option of splicing in a new wire. Of course it might be shared along the way with the cam sensor.

if you don’t know the low reference is a “clean” sensor ground within the ECM.

 

[Robinjo]

if you don’t know the low reference is a “clean” sensor ground within the ECM.

@Gtstorey (or anyone else that is strong with electrical understanding)
Will you expand on this points description a little more? A lot of us are still very green with electrical terminology and all. I'd like to understand this a whole lot more, so I'm sure there are others that would like to understand better as well.

I do know that all 6 of my wires from the APP went to PCM C1 end. By re-wiring that section it ended up solving my issue. Since there is no continuity between those two points this may be at least another culprit. Mine would run and drive in this condition though. It just had very little pedal response or power.

 

[Batmonkey]

well ive lost all communication with my tcm, scan tool wont read now. This was an intermittent problem, I thought I sorted it out, but apparently not. I did get the Low reference ground back though.

 

[Gtstorey]

You need to go through and tighten up all of your connections. The connectors aren't really designed to take apart multiple times and the individual contacts get loose. And when you start tracking down problems, you disconnect them more. If you aren't careful using meter leads, that can greatly increase the problems.

 

[Markm]

well ive lost all communication with my tcm, scan tool wont read now. This was an intermittent problem, I thought I sorted it out, but apparently not. I did get the Low reference ground back though.

Was the engine harness chaffed by the oil filter on the block? I had a boat load of wire repairs in that area on cobalts

 

[Hellproof]

If your TCM isnt communicating, it may be shorted out. Last year, I accidentally arced the positive post on the fuse block to ground for a tenth of a second. Not sure if it made contact with the TCM directly or just the frame, but it definitely arced in that area. A week later i tried to start it and it woukd get power but wouldnt crank at all. I spent a solid week checking every fuse and circuit continuity and everything checked out. On the last day I took a shot at just replacing the TCM from a company I found online that programs them to your VIN and ships them. As soon as I installed the new one it started right up and cleared all my codes. I can't remember all of the codes I had, but they looked similar to yours i believe.

My scan tool worked the whole time though, so your issue may be in the wiring.

All my research led to a bad ground near the starter being the culprit but turns out I just fried the TCM.

 

[Batmonkey]

You need to go through and tighten up all of your connections. The connectors aren't really designed to take apart multiple times and the individual contacts get loose. And when you start tracking down problems, you disconnect them more. If you aren't careful using meter leads, that can greatly increase the problems.

How would find a loose connector, and would you tighten it

 

[Ross]

They make Electrical Terminal Pin-Fit/Tension Testing Tools like this one, and they make Car Wire Terminal Removal Tool Kit like this.
It is a delicate job to check the tension on each connector, and make sure it has the right amount of drag on the pin.
If you find a loose connector pin, you need to remove the wire and terminal from the connector, then lightly squeeze it closed until you get the correct amount of drag, and then replace it in the connector.
If you have a box full of left over Cobalt connectors, you might be able to harvest a same size terminal connector from it, and replace a loose one.