Grumpy

Some info originally supplied by me, more from others, originally posted at DIY-EFI

Misc sensor info. and part nos.

MAP/pressure sensors
There are several varieties of pressure sensors from GM: Map sensors in 3 varieties (1 bar, 2 bar, 3 bar), and a barometric pressure sensor. 1 Bar sensors are good for NA engines, they measure from 0 (vacuum) to approximately atmospheric pressure. A 2 Bar sensor is good for 15 PSI of boost, and a 3 Bar unit is good for 30 psi of boost.
They all share a common pinout, although the connector keying may be different:

Pin A -- Ground
Pin B -- Sensor output
Pin C -- +5 volts
Version Part numbers Description
1 Bar GM part # 2503679
standard part # AS-5
Pretty much any normally aspirated TBI GM car, plus plenty of others
2 Bar GM part # 16009886
Wells part # SU-129
standard part # AS-4
91-93 GMC Syclone & Typhoon 4.3 turbo
87-90 Pontiac Sunbird Turbo 2.0
84-86 Sunbird (actually any J-car) turbo 1.8
3 Bar GM part # 16040749

Baro GM part # 1600683
Has a piece of foam over the pressure port.
100 Kpa, 4.9V 90 Kpa, 4.4V 80 Kpa, 3.8V 70 Kpa, 3.3V 60 Kpa, 2.7V 50 Kpa, 2.2V 40 Kpa, 1.7V 30 Kpa, 1.1V 20 Kpa, 0.6V 10 Kpa, 0.3V

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IAT/CTS sensors
IAT and CTS sensors (Inlet air temp and cooland temp). These are sensors that provide a variable resistance according to temperature. IAT is sometimes referred to as MAT (Mass Air Temp) Temperature (C) Temperature (F) IAT resistance CTS resistance
100 210 185 177
90 194 241
80 176 332
70 158 450 467
60 140 667
50 122 973
40 104 1800 1,459
30 86 2,238
20 68 3400 3,520
10 50 5,670
0 32 7500 9,420
-10 14 13,500 16,180
-20 -4 25,000 28,680
-30 -22 52,700
-40 -40 100,700 100,700