Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection
SENSOR AND CIRCUIT CHECK
1. With ignition turned OFF, disconnect ECM connector from ECM.
Intake Air Temperature Sensor:
2. Using DVM set to 1K ohm scale, check resistance between ECM harness connector terminals #44 and #30.
^ Resistance should be approximately that shown in diagram for a given temperature.
NOTE: Use your best educated guess as to what the air temperature is inside the throttle valve body. If the measured resistance indicates a temperature somewhere near your guess, chances are the sensor is OK.
If resistance is very high or infinite, check for:
a. Open circuit between ECM terminal #44 (W/Blk wire) and intake air temperature sensor.
b. Open sensor ground circuit between sensor and ECM terminal #30 (Blk/Brn wire).
. Faulty sensor.
If resistance is very low or zero, check for:
a. Grounded circuit between ECM terminal #44 and sensor.
b. Sensor wires pinched and shorted to each other.
c. Shorted sensor (faulty sensor).
SENSOR CHECK ONLY
1. With ignition turned OFF, disconnect ECM connector from ECM.
2. Remove idle stabilizer valve to access back of intake air temperature sensor, and peel back the rubber insulator boot from sensor.
3. Using DVM set to 1K ohm scale, check resistance between the bare wire ends where they are soldered to the sensor.
^ Resistance should be approximately that shown in diagram for a given temperature.
If resistance is very high or infinite, sensor is faulty.
If resistance is very low or zero, check for:
a. Sensor wires pinched and shorted to each other, or both sensor wires shorted to ground..
If wires are not shorted to each other or to ground, then sensor is faulty.
If sensor and wires check out OK, and a code 2322 was displayed with other codes, check for short to power or ground in knock sensor circuits. Also check for open ECM ground circuits (no ECM engine ground or poor connection).
If sensor and wires check out OK, and a code 2322 was displayed alone, then ECM is not reading sensor signal (faulty ECM).