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View Full Version : B1099 vs. C0803-0806 grams/sec conflicts



MN C5
September 9th, 2009, 03:23 PM
I'm having some issues with tuning MAF'less and was wondering what opinions there were on this topic.

B1099 shows a gms/sec limit of 2455.2471 at 15,000hz and C0803-0806 show and upper limit of 512 grams/sec.

So is the MAF still limited to 512 grams/sec as a hard ecm limit? Or does setting P0068 to "X:Not Reported" eliminate the C0803-0806 from the programing loop? Or is there something else affected by the 512 grams/sec limit in the C080X tables. I was hoping to dial in the VE table and hook the MAF back up. Will setting POO68 to not reported be enough to run more that the 512 grams/sec

GMPX
September 10th, 2009, 08:01 AM
What OS? Actually, that doesn't really matter, GM change the limits over time, they are hard coded limits in the ECM, not something we've decided on.

MN C5
September 10th, 2009, 08:23 AM
What OS? Actually, that doesn't really matter, GM change the limits over time, they are hard coded limits in the ECM, not something we've decided on.

Thanks for the reply! I'm trying to understand how tables C0803-06 affect the tune.

0803 "Used by the ETC diagnostic tests, this table defines the maximum expected measured airflow for a given RPM." So what happens when you exceed the max unit value of 512? Or if thats the expected maximum expected flow what does the PCM do when it sees a value greater than 512. I know GM had a hard limit of 512 on the last gen of OS's but this OS has much higher values at the higher frequencies, just wondering if once the values are larger than 512 if they are ignored or factored into fueling.

EngineCalibrations
July 25th, 2013, 05:41 AM
Thanks for the reply! I'm trying to understand how tables C0803-06 affect the tune.

0803 "Used by the ETC diagnostic tests, this table defines the maximum expected measured airflow for a given RPM." So what happens when you exceed the max unit value of 512? Or if thats the expected maximum expected flow what does the PCM do when it sees a value greater than 512. I know GM had a hard limit of 512 on the last gen of OS's but this OS has much higher values at the higher frequencies, just wondering if once the values are larger than 512 if they are ignored or factored into fueling.
I have the same question.