Grand Cherokee 2WD V8-5.2L VIN Y (1998)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
ENGINE COOLANT TEMPERATURE SENSOR
To perform a complete test of the engine coolant temperature sensor and its circuitry, refer to Powertrain Management/Computers and Control
Systems/Testing and Inspection.
See: Testing and Inspection
To test the sensor only, refer to the following:
Fig. 55 ECT - V8
1. Disconnect wire harness connector from coolant temperature sensor (Fig. 55).
2. Engines with air conditioning: When removing the connector from sensor, do not pull directly on wiring harness. Fabricate an L-shaped hook tool
from a coat hanger (approximately eight inches long). Place the hook part of tool under the connector for removal. The connector is snapped
onto the sensor. It is not equipped with a lock type tab.
CTS & IAT Resistance Chart Verses Temperature
3. 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 Coolant Temperature Sensor/Intake Air Temperature Sensor resistance chart. Replace the sensor if it is not within the
range of resistance specified in the chart.
4. Test continuity of the wire harness between the Powertrain Control Module (PCM) wire harness connector and the coolant sensor connector
terminals. Repair the wire harness if an open circuit is indicated.
5. After tests are completed, connect electrical connector to sensor. The sensor connector is symmetrical (not indexed). It can be installed to the