Is MAP a backup for MAF failure? ('95 LT1)
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Pro
Joined: Jun 2001
Posts: 708
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From: Florida
Is MAP a backup for MAF failure? ('95 LT1)
Been out of the tuning/logging loop for a while, but just decided to do some logging w/ DataMaster and came up with a DTC code 48 (MAF System Fail)... MIL not illuminated.
I thought that the MAP/Speed Density "took over" if there was a MAF fault, but when I disconnect the MAF the engine dies immediately. When I disconnect the MAP/Speed density (MAF still connected), the MIL illuminates and both fans come on, but engine stays running.
If the engine stays running w/ the MAP/Speed Density disconnected, is there REALLY a MAF fault?
My TunerCat file does NOT have "Speed Density Enabled" 'checked'. If it is 'checked', does that mean it's solely running on MAP/Speed Density or that MAP will "take over" if a MAF failure occured?
'95 LT1/4L60e
Thanks!
I thought that the MAP/Speed Density "took over" if there was a MAF fault, but when I disconnect the MAF the engine dies immediately. When I disconnect the MAP/Speed density (MAF still connected), the MIL illuminates and both fans come on, but engine stays running.
If the engine stays running w/ the MAP/Speed Density disconnected, is there REALLY a MAF fault?
My TunerCat file does NOT have "Speed Density Enabled" 'checked'. If it is 'checked', does that mean it's solely running on MAP/Speed Density or that MAP will "take over" if a MAF failure occured?
'95 LT1/4L60e
Thanks!
Melting Slicks
Joined: Jun 1999
Posts: 2,949
Likes: 23
From: Bowling Green KY
Old thread but pretty sure if you completely disconnect the MAF it will run in Speed Density mode, in fact I think this is the best way to develop the VE tables. I know my 96 w/ 95 PCM runs fine with the MAF disconnected.
But if it's connected I don't know that it will ever switch over to Speed Density, even with a MAF fault?
But if it's connected I don't know that it will ever switch over to Speed Density, even with a MAF fault?
