Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Hello and welcome to JA.
Your temp gauge is not hard wired to any sending unit for engine temp. It is a calculated value based on many inputs and it relayed to the instrument cluster via a digital computer message. The gauge reading that you are seeing is a calculated relative position on the scale based on engine load transmission load etc. In other words, your gauge and your engine are operating correctly. As long as your gauge does not run in the red you are fine. If you do have doubts about the actual temp the best thing to do would be to get a scan tool that can read data so that you can compare the readings of the ECT engine coolant temp sensor to your gauge non the dash. Her is the Chrysler service info description of the temp gauge.
The engine coolant temperature gauge gives an indication to the vehicle operator of the engine coolant temperature. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) on vehicles equipped with a gasoline engine, or the Engine Control Module (ECM) on vehicles equipped with a diesel engine over the Controller Area Network (CAN) data bus.
The engine coolant temperature gauge is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or START positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the OFF position. The instrument cluster circuitry controls the gauge needle position and provides the following features:
The PCM (gasoline engine) or ECM (diesel engine) continually monitors the engine coolant temperature sensor to determine the engine operating temperature. The PCM or ECM then sends the proper messages to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN). For further diagnosis of the engine coolant temperature gauge or the instrument cluster circuitry that controls the gauge. If the instrument cluster turns ON the check gauges indicator due to a high engine temperature gauge reading, it may indicate that the engine or the engine cooling system requires service.
For proper diagnosis of the engine coolant temperature sensor, the PCM, the ECM, the EMIC, the CAN data bus or the electronic communication related to engine coolant temperature gauge operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.