The 2019 Ram 2500's P0182 code indicates the Fuel Temperature Sensor A circuit voltage is lower than expected. This causes the ECU to interpret fuel as extremely cold, affecting fuel injection calculations. Understanding whether it's an electrical fault or actual sensor issue helps direct the repair.
What P0182 Means
P0182 indicates fuel temperature sensor voltage is below minimum threshold. The sensor is a thermistor—low voltage corresponds to high resistance, indicating cold temperature. Very low voltage suggests either an open circuit or a sensor stuck in cold-reading mode.
Ram 2500 Diesel Considerations
The 2019 Ram 2500 commonly uses the 6.7L Cummins diesel. Diesel fuel temperature monitoring is particularly important because diesel fuel characteristics change significantly with temperature. Cold diesel is denser and requires different injection timing than warm diesel.
Common Causes of P0182
An open circuit in the fuel temperature sensor wiring causes maximum resistance (minimum voltage). Damaged wiring, disconnected connector, or sensor element failure creates this condition.
A failed sensor with open thermistor element outputs minimum voltage. Internal component failure opens the circuit, reading as extremely cold.
Corroded or damaged connector terminals create high resistance, causing low voltage readings that may trigger this code.
Diagnostic Approach
Check the sensor connector for security and corrosion. Monitor fuel temperature readings—if showing extreme cold (-40°F) when actually warm, the circuit is open. Test sensor resistance at known temperature against specifications—infinite resistance indicates an open sensor.