Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

TESTING PROCEDURE:

NOTE: While trouble shooting, always check the wiring, fuses and connectors for good condition and routing. Use the wiring diagrams found in SCHEMATIC DIAGRAMS to supplement your testing efforts.

Color Code Legend:

Checking ECU Ground Connections:

1. Turn ignition OFF.
2. Access fuel injection ECU by removing the passenger side kick panel and glove compartment.
3. Check fuel injection ECU ground connections. They should make good contact and fit tight.

Removing ECU Connector:

4. Remove fuse #1 (located in central electric unit behind ash tray) to interrupt the power supply. Then remove the ECU connector by pressing up the latch and folding out the wire cluster.

Removing Protective Sleeve:

5. Remove connector protective sleeve and reinstall fuse #1 for testing.
CAUTION: ^ Never check connections from the front. Connectors can get damaged and worsen the problem.
^ Check connections through the holes in the connector.
^ Connection pin numbers are printed on the connector side.

Checking Resistance Between Pin 6 And 10:

6. Connect an ohmmeter between pin 6 and 10. Resistance should be as follows at:

-4°F (-20°C) = approx. 15'000 ohms
68°F (20°C) = approx. 2'500 ohms
212°F (100°C) = approx. 160 ohms

Intake Air Temperature Sensor Resistance Chart:

7. If possible, check resistance at various temperatures by warming the sensor with a hot air blower.
8. If measurement is not within specifications, retest at sensor.
a. If measurement is again out of specifications, replace and retest with new intake manifold temperature sensor.
b. If measurement is now within specifications, repair wiring or connectors to ECU.
9. Disconnect the test equipment. Remove the #1 fuse and reconnect the ECU and all other connectors, install the kick panel and glove compartment. Ensure that the rubber seal in the ECU connector is installed before it is connected to the unit.
10. Reinstall the #1 fuse.