Dakota 2WD V8-4.7L (2008)
Outside Temperature Display Sensor: Testing and Inspection
AMBIENT TEMPERATURE SENSOR
The temperature function is supported by the ambient temperature sensor, a wiring circuit, and the Front Control Module (FCM). When the sensor is
exposed to temperatures above 60° C (140° F), or if the sensor circuit is shorted, 60° C (130/140° F) will appear in the display in place of the
temperature. When the sensor is exposed to temperatures below - 40° C (- 40° F) or if the sensor circuit is open, - 40° C (- 40° F) will appear in the
display.
The ambient temperature sensor circuit can be diagnosed using the following Temperature System Test, and Sensor Test. If the temperature sensor and
circuit are confirmed to be OK, but the temperature display is inoperative or incorrect, test the Compass Mini - Trip Computer (CMTC),See: Instrument
Panel, Gauges and Warning Indicators/Compass/Testing and Inspection.
TEMPERATURE SYSTEM TEST
For complete circuit diagrams, refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness
connectors, splices and grounds.
NOTE: Temperature readings do not update immediately. Allow up to 60 seconds after the ignition switch is turned to the On position for
readings to meet test specifications.
1. Turn the ignition switch to the Off position. Disconnect the wire harness connector from the ambient temperature sensor.
2. Turn the ignition switch to the On position. The CMTC display should now read - 40° C (- 40° F). If OK, go to STEP 3. If not OK, repair the
shorted sensor return circuit or ambient temperature sensor signal circuit to the ambient temperature sensor as required.
3. Turn the ignition switch to the Off position. Taking care not to damage the wire terminals, connect a jumper wire between the two terminals in the
body half of the ambient temperature sensor harness connector.
4. Turn the ignition switch to the On position. The CMTC display should now read 60° C (130/140° F). If OK, go to STEP 5. If not OK, repair the
open sensor return circuit or ambient temperature sensor signal circuit to the ambient temperature sensor as required.
5. Clear any Diagnostic Trouble Codes that may have been set while performing the test. Perform further diagnosis of the Compass Mini - Trip
Computer (CMTC),See: Instrument Panel, Gauges and Warning Indicators/Compass/Testing and Inspection as needed.
SENSOR TEST
1. Turn the ignition switch to the Off position. Disconnect the ambient temperature sensor harness connector.
2. Measure the resistance of the ambient temperature sensor. At - 40° C (- 40° F), the sensor resistance is 336 kilohms. At 55° C (130° F), the sensor
resistance is 2.488 kilohms. The sensor resistance should read between these two values. If OK, perform further diagnosis of the Compass Mini -
Trip Computer (CMTC),See: Instrument Panel, Gauges and Warning Indicators/Compass/Testing and Inspection