View Full Version : P0103 set, action taken?
Boost
December 9th, 2015, 03:32 AM
I am working on an LS1 that has hard / current P0103 (Mass Airflow / MAF sensor circuit high) set. The mechanics tried replacing the sensor several times... :doh: Anyway my question is, what is the action taken by the PCM? Could it be that it stops looking at the MAF and defaults to speed density? Reason I ask is because it was MAF tuned for mods but gets poor fuel economy and nearly stalls from excessive fuel on deceleration. Thanks
joecar
December 9th, 2015, 05:15 AM
Disagnosing P0103 (http://www.gearchatter.com/viewtopic9068.php)
On presence of any of the MAF DTC's the PCM stops using MAF and uses VE only (yes, speed density).
Boost
December 10th, 2015, 04:18 AM
Just as I suspected, thank you so much for your phenomenal replies Joe!
Boost
December 10th, 2015, 04:26 AM
Disagnosing P0103 (http://www.gearchatter.com/viewtopic9068.php)
On presence of any of the MAF DTC's the PCM stops using MAF and uses VE only (yes, speed density).
I won't move much further until diagnosed and repaired correctly, just wondering though - seems they tried to block it. In my experience this usually does not prevent PCM from defaulting to VE (?)
joecar
December 10th, 2015, 10:05 AM
MAF DTC forces PCM to use VE/SD...
if you set the DTC to Not-Reported, then PCM will not use VE/SD, it will continue to use the MAF (or try to).
This is why you want VE to be properly tuned/corrected.
Boost
December 12th, 2015, 08:57 AM
MAF DTC forces PCM to use VE/SD...
if you set the DTC to Not-Reported, then PCM will not use VE/SD, it will continue to use the MAF (or try to).
This is why you want VE to be properly tuned/corrected.
Understood. Thank you SO much!
Boost
December 12th, 2015, 12:02 PM
19087
Yup...
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