LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 1991 >> APV >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Computerized Engine Controls >> Engine Sensors & Switches >> Manifold Air Temperature (Mat) Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Manifold Air Temperature (Mat) Sensor

If a MAT sensor-related code is present, see the appropriate article below:

An out-of-calibration sensor may not set a trouble code. Use following procedure to test calibration. Disconnect MAT sensor harness connector. Connect ohmmeter between sensor terminals. Sensor resistance should be as specified. See MAT SENSOR RESISTANCE table. With vehicle sitting overnight, MAT sensor and coolant sensor should have close to the same resistance reading.

MAT SENSOR RESISTANCE

Temperature °F (°C) Resistance (Ohms)
210 (100) 185
160 (70) 450
100 (38) 1800
70 (20) 3400
40 (4) 7500
20 (-7) 13,500
0 (-18) 25,000
-40 (-40) 100,700