Testing Ford Sensors Part 2


TESTING Disengage the engine wiring harness connector from the ECT sensor.
1. Connect an ohmmeter between the ECT sensor terminals, and set the ohmmeter scale on 200,000 ohms.
2. With the engine cold and the ignition switch in the OFF position, measure and note the ECT sensor resistance.
3. Attach the engine wiring harness connector to the sensor.
4. Start the engine and allow the engine to warm up to normal operating temperature.
5. Once the engine has reached normal operating temperature, turn the engine OFF
6. Once again, detach the engine wiring harness connector from the ECT sensor. Measure and note the ECT sensor resistance, then compare the cold and hot ECT sensor resistance measurements with the accompanying chart.
7. Replace the ECT sensor if the readings do not approximate those in the (see IAT-ECT chart), otherwise re-attach the engine wiring harness connector to the sensor. Alternately you can also submerge the end of the temperature sensor in cold or hot water and check resistance as another way to check this sensor.




TESTING WARNING:Do not pierce the wires when testing this sensor; this can lead to wiring harness damage.
Back probe the connector to properly read the voltage of the HO2S. Disconnect the HO2S sensor.
1. Measure the resistance between PWR and GND terminals of the sensor (Usually the Black and White).
If the reading is approximately 6 ohms at 68°F (20°C). the sensor’s heater element is in good condition.
2. With the HO2S connected and engine running, measure the voltage with a Digital Volt-Ohmmeter (DVOM) between terminals HO2S and SIG RTN (GND) Can be black and gray or green, of the oxygen sensor connector.
If the voltage readings are swinging rapidly between 0.01–1.1 volts, the sensor is probably okay.

Oxygen Sensor
Oxygen Sensor

Be Sociable, Share!

Posted under

This post was written by admin on July 2, 2010

Leave a Comment





CommentLuv badge

Spam Protection by WP-SpamFree

Security Code: