Default C6 MAF and Schematics and diagnostics

I have been mending my wiring harness in my 2008 C6Z06.

Gearing up for first start I am checking sensors and DTCs. I have two current codes
P2123 Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage ECM
P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage ECM

My ambient and manifold temperatures are good.

IAT2 sensor doesn't apply to my vehicle but the channel template had that extra. question is, which high IAT sensor is the DTC P0113 referring to? Is that in the MAF? IAT1? Or Manifold Air Temp? which wiring do I check

as well as the pedal position as noted in the codes. Please see the screenshot below.

I want to verify that I did not mess anything up when fixing the harness looms and I did not break any connections first. This is going to be tedious but I want to make sure I'm not missing anything.

Turns out the culprit was damaged wiring at X180 connector from aging wiring.

I would like to check continuity on the maf sensor pigtail to ecu and the pedal pigtail to ecu. if you have the schematics or diagrams of which pin to check on what bulkhead connector, this would be appreciated. again this is step 1. My next step is to verify that all sensors are good. The MAF is good (I checked my current maf on another car when not running). I do not know if the pedal sensor is good, due to not having another compatible vehicle.

If you have any suggestions, glad to hear them.
Attachment 138955

With MAF 5-way unplugged it should have ~5V on E & ground on D. Check it in the scanner unplugged, and then with E/D shorted together.

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Originally Posted by blindsquirrel

With MAF 5-way unplugged it should have ~5V on E & ground on D. Check it in the scanner unplugged, and then with E/D shorted together.

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Attachment 138956

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Thank you for your reply. I am a very stupid person. Does this mean I should:

• Check voltage on E with my multimeter on 20V, one lead on the pigtail E and one lead on the chassis ground? or to battery positive?

• Check continuity with my multimeter on D with one lead on the pigtail D and one lead on the chassis ground?

• and the third on your reply - is that one multimeter lead on E pigtail and one lead on D pigtail? what am i measuring?
  

Thanks for any clarification.

I don't mean to be rude but with those kinds of questions you are not ready to tackle this yourself, not right now. Not saying you can't get there with some effort, but this is about as basic as basic electrical stuff can get.

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Originally Posted by blindsquirrel

I don't mean to be rude but with those kinds of questions you are not ready to tackle this yourself, not right now. Not saying you can't get there with some effort, but this is about as basic as basic electrical stuff can get.

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Whether you meant to or not, that is rude. It's not for you to decide whether I am ready to tackle this myself.

I have the tools required to perform this diag, but your abridged recommended procedure isn't descriptive enough to be helpful to me at the moment. This is why I asked for clarification. If you do not want to provide any further help, I don't blame you, just move on. Don't try to gatekeep me from fixing my car. Thanks.

Being honest isn't rude. The instruction he gave you are very basic electrical instructions. About the only other thing he could do is make you a video on the exact vehicle with your exact voltmeter.

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Originally Posted by gtstorey

Being honest isn't rude. The instruction he gave you are very basic electrical instructions. About the only other thing he could do is make you a video on the exact vehicle with your exact voltmeter.

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Completely disagree; it is rude. "You don't know as much as me, therefore you shouldn't work on your car" :crazy:

I replied with clarification questions - it's as simple as replying to those clarifications. If that's too much effort for anyone else to revise then so be it - I'll keep waiting until some kind soul comes and spells it out for me.

My interpretation of what he said is "you don't know enough to be trying to work on this problem and are as likely to mess something else up as to fix this problem". I've spent a lot of time trying to help people trouble shoot electrical issues on another forum, and it rarely goes well when you have to give instructions on how to use the meter.

For example in your request for clarification not only do you have to set the meter to 20v, but it must be the "DC" setting. And you have to make sure your leads are plugged into the correct terminals on the meter. I've had to request pictures of the meter as they have set it up to get just basic measurements before.

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Originally Posted by blindsquirrel

I don't mean to be rude but with those kinds of questions you are not ready to tackle this yourself, not right now. Not saying you can't get there with some effort, but this is about as basic as basic electrical stuff can get.

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This is about as sugar coated as you get. Makes me question you being a mechanic. Hahahaha

Don't worry about the permanent code for IAT circuit high, possibly turned off by tuner previously and may be why its there. The only issue you have at the moment is the Accelerator pedal position is showing full pedal position. would be worth checking the wiring for rub and verify the pedal voltage is rising and falling correctly with a multi meter.

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Originally Posted by gtstorey

My interpretation of what he said is "you don't know enough to be trying to work on this problem and are as likely to mess something else up as to fix this problem". I've spent a lot of time trying to help people trouble shoot electrical issues on another forum, and it rarely goes well when you have to give instructions on how to use the meter.

For example in your request for clarification not only do you have to set the meter to 20v, but it must be the "DC" setting. And you have to make sure your leads are plugged into the correct terminals on the meter. I've had to request pictures of the meter as they have set it up to get just basic measurements before.

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Thank you for your additional clarification. I am using DC. I am using the common port for ground, and the Voltage Ω mA port for the positive lead. I don't feel offended by you explaining it, it is appreciated.

How do I test to make sure I see 5V DC on terminal E? Please complete my description here: Vehicle ON, MAF unplugged - Multimeter on 20V DC. One lead on terminal E of the harness sensor male pigtail. What is the other multimeter lead connected to read 5V DC?
How do I test to make sure I see ground on terminal D?Please confirm my description here: Vehicle ON, MAF unplugged - Multimeter on continuity alarm ->|-. One lead on terminal D of the harness sensor male pigtail. Second lead on chassis ground or run a wire to battery negative terminal and confirm continuity.

The third component of the original reply - I believe I understand it is to run a scan and see how it changes when terminal D and E are shorted - if it goes from 5V to ground? How should I set up those two channels on HP tuners? This i may need specific instructions. The current layout template was provided to me so that I could run a log.

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Originally Posted by dangrebel

Don't worry about the permanent code for IAT circuit high, possibly turned off by tuner previously and may be why its there. The only issue you have at the moment is the Accelerator pedal position is showing full pedal position. would be worth checking the wiring for rub and verify the pedal voltage is rising and falling correctly with a multi meter.

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There hasn't been any changes to the HP tuners configuration or MAF codes since before the motor came out. I am trying to determine if it was damaged during the reinstallation of the motor.

I am going to attempt to check the pedal voltage, same question as before on the MAF - one lead of the multimeter on the 5v signal of the pigtail and the other lead goes where? assumption is that the vehicle is ON and the plug is INSTALLED on the pedal, and measuring voltage from an exposed 5v signal lead of that pigtail. correct?

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Originally Posted by TheMechanic

This is about as sugar coated as you get. Makes me question you being a mechanic. Hahahaha

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Where's the like button LOL

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Originally Posted by nocopnostopp

I have been mending my wiring harness in my 2008 C6Z06.

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OK I'll try to be on my best behavior.

Here's where we need to start. Reason being, your non engine running scan data looks normal other than the throttle pids, so you can assume the powers and grounds are good.

The throttle body and pedal sensor both are grounded through the PCM. Chances are you screwed something up.

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Originally Posted by edcmat-l1

OK I'll try to be on my best behavior.

Here's where we need to start. Reason being, your non engine running scan data looks normal other than the throttle pids, so you can assume the powers and grounds are good.

The throttle body and pedal sensor both are grounded through the PCM. Chances are you screwed something up.

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Thanks for chiming in. The IAT 2 is at 32F (it was 80F at the time of the log, as shown on the other sensor readings). A quick search on corvette forums yielded the result that IAT2 is measured at the MAF. This is why I was thinking there is something wrong with that sensor or at least the wiring.

How can I check the PCM ground as you had mentioned?

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Originally Posted by nocopnostopp

Thanks for chiming in. The IAT 2 is at 32F (it was 80F at the time of the log, as shown on the other sensor readings). A quick search on corvette forums yielded the result that IAT2 is measured at the MAF. This is why I was thinking there is something wrong with that sensor or at least the wiring.

How can I check the PCM ground as you had mentioned?

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You don't have an IAT2. This is the problem with you or anyone of your experience level trying to tackle this. Sorry but that's just the truth of the matter.

So are you here to help me learn? Or you just going to keep putting me down while I try to improve my knowledge? I don't care about your opinions regarding whether I should tackle it or not. Complain about that somewhere else please. Or just don't reply. It's basically trolling at this point.

I tested the ground on the MAF and it was continuous to a chassis ground with the vehicle ON. How do I check the voltages - seems like it is some trade secret that the three people on this thread want to keep classified against Chinese interests. Where do I put the other lead?

I did not modify any of the throttle body wiring, however I am interested in verifying the integrity of the wiring. From the description of the pins in the screenshot - it doesn't seem that there is a ground that I can check. Again, please advise how to check the voltage.

Attachment 138959

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Originally Posted by nocopnostopp

So are you here to help me learn? Or you just going to keep putting me down while I try to improve my knowledge? I don't care about your opinions regarding whether I should tackle it or not. Complain about that somewhere else please. Or just don't reply. It's basically trolling at this point.

I tested the ground on the MAF and it was continuous to a chassis ground with the vehicle ON. How do I check the voltages - seems like it is some trade secret that the three people on this thread want to keep classified against Chinese interests. Where do I put the other lead?

I did not modify any of the throttle body wiring, however I am interested in verifying the integrity of the wiring. From the description of the pins in the screenshot - it doesn't seem that there is a ground that I can check. Again, please advise how to check the voltage.

Attachment 138959

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I just told you you don't have an IAT2. Which one of us is here to learn?

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Originally Posted by edcmat-l1

I just told you you don't have an IAT2. Which one of us is here to learn?

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Originally Posted by edcmat-l1

The throttle body and pedal sensor both are grounded through the PCM. Chances are you screwed something up.

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Apparently both of us since you literally just said to check the throttle body ground.

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Originally Posted by nocopnostopp

Apparently both of us since you literally just said to check the throttle body ground.

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Where did I say that?

There's one of this in this thread that's qualified to do the work you're trying to do.