RAM 1500 Truck 2WD V8-4.7L VIN N (2002)
Thermostat: Testing and Inspection
DIAGNOSIS AND TESTING-THERMOSTAT
ON-BOARD DIAGNOSTICS
All gasoline powered models are equipped with On-Board Diagnostics for certain cooling system components. If the powertrain control module
(PCM) detects low engine coolant temperature, it will record a Diagnostic Trouble Code (DTC) in the PCM memory. Do not change a thermostat for
lack of heat as indicated by the instrument panel gauge or by poor heater performance unless a DTC is present.
The DTC can also be accessed through the DRBIII scan tool.