[John T Stein]

Bruce Bowling wrote:
> 
> Does the GM MAP sensor put out a 0-5 volt signal? (I have always wondered).
> If so, could someone out there elaborate (on pinout, range, etc.)?
> 
> - Bruce


GM MAP sensors put out a 0-5 volt signal as you would expect.  Be 
careful however, some of the GM MAPs have a positive scale factor and 
read ~5 volts at atmospheric pressure and ~ 0 at ~30 inches Hg vacuum 
while others have a NEGATIVE scale factor. This second type reads ~5 volts
at ~ 30  inches Hg and 0 volts at atmospheric pressure.  From experience, the 
sensor GM used on the '83 2.8 L v-6 was the second type while that 
used on the '87 2.5 L four was the first type.

John