RAM 3500 Truck 4WD V10-8.0L VIN W HDC (1999)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
To perform a complete test of the Engine Coolant Temperature (ECT) sensor and its circuitry, refer to DRB scan tool and appropriate Powertrain
Diagnostics Procedures. To test the sensor only, refer to the following:
Engine Coolant Temperature Sensor
1. Disconnect wire harness connector from coolant temperature sensor.
Sensor Resistance (Ohms) - Coolant Temperature Sensor/Intake Air Temperature Sensor Chart
2. Test the resistance of the sensor with a high input impedance (digital) volt-ohmmeter. The resistance (as measured across the sensor terminals)
should be as shown in the SENSOR RESISTANCE (OHMS)-COOLANT TEMPERATURE SENSOR/IN- TAKE AIR TEMPERATURE
SENSOR chart. Replace the sensor if it is not within the range of resistance specified in the chart.
3. Test continuity of the wire harness between the PCM wire harness connector and ECT sensor connector terminals. Repair the wire harness if an
open circuit is indicated.
4. After tests are completed, connect electrical connector to sensor.
