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Thread: Need some help tuning sc silverado

  1. #1
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    Tuning sc silverado dtc's and maf

    2019 Silverado whipple supercharged 6.2 with a CAI and Cat-back. I didn't have the time last year, so I paid to have it tuned, but it still is not where it needs to be. Checking out recent logs, looks like the MAF is still not accurate and the torque model is off. I've also recently been getting CEL with codes I haven't seen before. They are pretty random, popping up every few days. Codes are below. Hoping for some insight to point me in the right direction. I don't think the tune is far off. Any suggestions for next steps?

    In going through the tune it looks like my original tuner left DFCO off (enable temp) and LTFT off (LTFT Min MAP vs Baro left set at 200kPa). Is there any reason I'd want to leave these disabled?

    Attached the tune and a couple of logs. Any help or pointing me in the right direction would be greatly appreciated.




    CEL Codes
    P015D O2 sensor delayed response - Lean to rich (Bank 2 Sensor 1)
    P00c7 Intake Air Pressure Measurement System - Multiple Sensor Correlation.

    Also Noticed these codes stored in memory when clearing the above. I related it to something going wrong when flashing a new tune, but thought I'd check if anyone has better insight.
    U0100 Lost Com. with ECM, stored in memory three times
    U0415 Invalid Data from ABS Control Module
    UO0422 Invalid data received from BCM.
    Attached Files Attached Files
    Last edited by Darkhorse220; 04-07-2022 at 11:07 AM. Reason: Clarify

  2. #2
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    Quote Originally Posted by Darkhorse220 View Post
    2019 Silverado whipple supercharged 6.2 with a CAI and Cat-back. I didn't have the time last year, so I paid to have it tuned, but it still is not where it needs to be. Checking out recent logs, looks like the MAF is still not accurate and the torque model is off. I've also recently been getting CEL with codes I haven't seen before. They are pretty random, popping up every few days. Codes are below. Hoping for some insight to point me in the right direction. I don't think the tune is far off. Any suggestions for next steps?

    In going through the tune it looks like my original tuner left DFCO off (enable temp) and LTFT off (LTFT Min MAP vs Baro left set at 200kPa). Is there any reason I'd want to leave these disabled?

    Attached the tune and a couple of logs. Any help or pointing me in the right direction would be greatly appreciated.




    CEL Codes
    P015D O2 sensor delayed response - Lean to rich (Bank 2 Sensor 1)
    P00c7 Intake Air Pressure Measurement System - Multiple Sensor Correlation.

    Also Noticed these codes stored in memory when clearing the above. I related it to something going wrong when flashing a new tune, but thought I'd check if anyone has better insight.
    U0100 Lost Com. with ECM, stored in memory three times
    U0415 Invalid Data from ABS Control Module
    UO0422 Invalid data received from BCM.
    You're correct that the MAF curve needs some work and the VT table does as well.

    As far as the odd DTC's, I would look at the ECM connector. Make sure that it's seated properly and snapped in place. I had one that had several random DTC's similar to yours. It had antifreeze in the main ECM connector. They guy told me that the radiator hose blew off and antifreeze covered the engine bay.

  3. #3
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    Thanks for the tip on ECM connector. I'll check it out. Didn't think of checking it before, but pretty sure that would cause the codes and some of the infrequent issues Ive seen.
    I'll need to work to work on the MAF. With the negative stft, I need lower airflow lb/hr in the MAF frequencies with negative fuel trims, correct?

  4. #4

  5. #5
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    Thanks and good point. I did double check MAP linear and offset. Both were correct for the LT4 MAP I'm running. I re-flashed tune and haven't seen a dtc since.

    Seems like i run into a decent amount of issues when flashing. Sometimes the write times out or i just end up with a write failed.

    Haven't had the chance to log and tune airflow yet. Need to go through the tune and see what was turned off and what limits were set where. I don't had a full grasp of how it was setup yet.

  6. #6
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    Quote Originally Posted by JANNETTYRACING View Post
    P007c indicates you have the wrong MAP sensor data for your sensor.
    That's not it. It's a rationality diagnostic. This is a result of the perceived MAP discrepancy between post-rotor measured MAP and the value calculated by airflow vs throttle position. It's sensitive enough to detect that there is more airflow than there should be through the throttle because the blower is drawing the inlet pressure down. Without installing and enabling an inlet pressure sensor, there's no good way to solve this.

  7. #7
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    Quote Originally Posted by smokeshow View Post
    That's not it. It's a rationality diagnostic. This is a result of the perceived MAP discrepancy between post-rotor measured MAP and the value calculated by airflow vs throttle position. It's sensitive enough to detect that there is more airflow than there should be through the throttle because the blower is drawing the inlet pressure down. Without installing and enabling an inlet pressure sensor, there's no good way to solve this.
    Thank you, I am very aware of why these codes will set.

    You can't tell me that if the MAP sensor data is wrong it won't set this code.

    This is the most common reason why this code sets after a supercharger install.

    The supercharger companies can't make up there mind what map sensor they want to use this week.

    I have to have my customers send me pictures of the sensor before I will make a Calibration.

    Ted.

  8. #8
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    Thanks smokeshow. Your insight and knowledge on this forum has helped me a ton. l like to truly understand the why, to improve or avoid chasing ghosts.
    I've got another question. I'm working on dialing in the backwards e90 MAF table and I believe you can edit the axis of MAF frequencies. Why not chop off the front of the table? MAF shouldnt see below 900Hz WOT.

  9. #9
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    Quote Originally Posted by Darkhorse220 View Post
    Thanks smokeshow. Your insight and knowledge on this forum has helped me a ton. l like to truly understand the why, to improve or avoid chasing ghosts.
    I've got another question. I'm working on dialing in the backwards e90 MAF table and I believe you can edit the axis of MAF frequencies. Why not chop off the front of the table? MAF shouldnt see below 900Hz WOT.
    I often alter the Axis to give me more resolution, but do so at your own risk.

    Ted.

  10. #10
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    My plan was to dial MAF in a bit closer and then decide if i should change the table axis.. but was chasing my tail. Think the ecm was trying to interpolate too much with the curve.
    Edited the axis for better resolution and changes are responding much better / more predictable. Wasn't sure if anyone else had similar experience on the e90. Might just be a lack of knowledge/experience on my part.