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Mat Sensor Test

  1. Disconnect wire harness connector from MAT sensor. Test resistance of sensor with a high impedance digital ohmmeter. Resistance should be less than 1000 ohms with engine warm. Replace sensor if resistance is not within specified range. See TEMPERATURE-TO-RESISTANCE VALUES  table.
  2. Test resistance of wire harness between ECU wire harness connector terminal D-3 and sensor connector terminal. Repeat test with terminal C-8 at ECU and sensor connector terminal. Repair wire harness if an open circuit or resistance is greater than one ohm is indicated.
TEMPERATURE-TO-RESISTANCE VALUES (CTS & MAT SENSOR)

°F °C (Approximate) Ohms
212 100 185
160 70 450
100 38 1600
70 20 3400
40 4 7500
20 -7 13,500
0 -18 25,000
-40 -40 100,700