Cant Throw P0102 P0103 Codes for Speed Density

Like the titles says I cannot trigger P0102 and/or P0103 codes required to enter Speed Density mode. The car will crank but wont start.

Interestingly enough once the codes are thrown (I was able to get it thrown once a couple of weeks ago) the car will start up just fine. I was able to Log Afr error % and tune the VE for idle and installed larger injectors (80lb's) and get that running and idling.

Once I upgraded to the 2 Bar OS ("Write Entire") the P0102 & P0103 codes were erased and the car was back to cranking but not starting.

I cant get the car started long enough to trigger the codes but when I log the MAF Freq. PID I see that it is over 0Hz (which should Fail the MAF) and I just dont understand why it wont fail.

I've searched and read and read with no luck. I've tried all the usual suspects to fix the issue that I will list below:

Engine Diag>Airflow>MAF Frequency Fail High - Set to 0 and/or 1 Hz

Maximum Delta Airflow - P0101 Error - Set table to 0

DTCs P0101, P0102 & P0103 set to MIL on First Error (I also tried changing the settings on these to other Error Modes to see if that fixed the issue)

Engine>Airflow>MAF Calibration Airflow vs. Frequency - Set the cells to 15 g/s in hopes that it would allow the car to idle long enough to throw the codes.

Engine>Airflow>Dynamic> MAF Airmass Filt, High RPM Disable, High RPM Hyst all set to 0

Can't you unplug with key on/cranking and set dtc's? Then plug back in so IAT reads? Should run unplugged anyway.
I would also post a tune.

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Originally Posted by DGS

Can't you unplug with key on/cranking and set dtc's? Then plug back in so IAT reads? Should run unplugged anyway.
I would also post a tune.

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You'd think that. But, it isnt working for me.

I should have clarified that I have already wired in a stand alone IAT sensor and removed the wired from the 5 Pin MAF so that they are separate.

When I have the MAF plugged in it oscillated a Hz frequency while cranking. When I unplug the MAF there is no Frequency reading from the MAF Freq. PID (which is correct).

In either case the codes will not throw.

Tune file attached.

Thank you for responding.

Attachment 86193

The high rpm disable needs to be set above 0rpm, read the table. Set it to 8,000rpm because it says above this value to use filtered MAF data.

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Originally Posted by 5FDP

The high rpm disable needs to be set above 0rpm, read the table. Set it to 8,000rpm because it says above this value to use filtered MAF data.

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I only input 0 in that field as I read on a thread that may be a way to help the MAF fail with more expediency.

I believe that the stock setting for this cell is something like 4,000 rpm so, for the majority of the startup attempts the value would be well outside of the rpm range during cranking.

Either way I'll make the change and try that out.

Thanks for putting some eyes to this for me. I appreciate it.

Which Intake air temp sensor did you use

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Originally Posted by uarperformance

Which Intake air temp sensor did you use

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Its sold on Amazon. Replacement for an LS1 style 2 wire IAT. Not sure if I can post links so this is what the description says.

LIAMTU Intake Air Temperature Sensor Fast Response IAT Replaces Genuine GM Part 25036751 25037334

I don't know if this can play a roll in the issue or not. What I can say is the the IAT PID in the Scanner is showing the correct inlet temp (or approximately correct) considering my conditions and in relation to coolant temperature (when car is cold).

Curious as to why you asked that question? Have you seen that cause the same issue in the past?

At this point I'm all ears for solutions.

Thank you for taking the time to reply. I appreciate the insights.

Well no but we have a S-10 with 415 cu inch we just built. It came in with a blown up motor. It has a 2002 chevy pick up ecu in it. So it seems to be similar enough to see where the issue is. We have a truck 105 MM intake and 105 throttle body. There really isn't room for mass air flow sensor in the truck so we need a air temp sensor kit for it. We used a 1 bar set up so far. with no mass airflow it starts up a bit wonky for a flare condition. Looking at comparison tune I don't have the some of the items you have listed changed but mine sets the 103 code. If I tell it not to report that code it doesn't run without alot of help.

What are the color wires you wired the sensor into. I can check to see if they are in fact correct ones. Just for giggles.

Dynamic Air needs to be set to high RPM to keep it in blended mode while the MAF is failing.

We don't have access to the parameters in HPTuners but there are parameters that define how long the engine must be running and how many tests the MAF must fail before it trips the DTC. Setting all those "hidden" parameters to zero will instantly fail the MAF as soon as the engine cranks over thus keeping it in SD.

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Originally Posted by LSxpwrdZ

Dynamic Air needs to be set to high RPM to keep it in blended mode while the MAF is failing.

We don't have access to the parameters in HPTuners but there are parameters that define how long the engine must be running and how many tests the MAF must fail before it trips the DTC. Setting all those "hidden" parameters to zero will instantly fail the MAF as soon as the engine cranks over thus keeping it in SD.

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So what your saying is even without a mass airflow it will use the blended table until the maf fails?

Yes this is why you must populate the first cell of the maf table with some amount of airflow so it has something to run on before the maf fully fails. And also why the dynamic airflow disable rpm needs to be set high so it will actually look at the VE table once it's fired up. With it set to zero or 200rpm, as soon as the engine fires it doesn't look at VE model.