Computer Diagnostics and Tuning Technical discussion on diagnostics and programming of the F-body computers

pcm bad?

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Old Jun 10, 2009 | 04:19 PM
  #1  
ghost97ta's Avatar
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From: lamar mo
pcm bad?

well my car has not ran good in a long time.the pcm wont go to open loop or closed loop i think it is in safe mode ? cant clear any codes mass air meter
is showing 8.9 volts at idel . cant tune it wont let you in.
the car is 97 ta
Old Jun 10, 2009 | 05:22 PM
  #2  
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From: Hell was full so they sent me to NJ
If the MAF sensor is only getting 8.9V, its either got a faulty wire in the circuit, or the system voltage is so low that 8.9V is all it can supply. What does the dash gauge read when the pink MAF power wire is only getting 8.9V? If the system voltage it too low, the PCM isn't going to be able to respond to much of anything.
Old Jun 13, 2009 | 08:28 AM
  #3  
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From: lamar mo
yes it 12 volts to the pink wire .but when you look at mass air meter
on a scanner when the car is running at a idle. the mass air meter shows
8.9 volts which i was told the car thinks it going 80mph at idle.
Old Jun 13, 2009 | 01:40 PM
  #4  
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From: Hell was full so they sent me to NJ
Putting a scanner on the PCM will read the MAF air flow in "grams per second" (g/s), not volts. 8.9 g/s is a typical reading with the engine idling. How would the MAF reading translate to the car going 80 MPH?
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