The engine coolant temperature (ECT) sensor 2 is a variable resistor that measures the temperature of the engine coolant. The engine control module (ECM) supplies 5 volts to the ECT 2 signal circuit, and a ground for the ECT 2 low reference circuit.

P2184

The ECM detects that the ECT Sensor 2 parameter is warmer than 149°C (300°F) for more than 15 seconds. This is equal to less than 0.065 volt on the ECT sensor 2 signal circuit as measured by the ECM.

P2185

The ECT sensor 2 temperature is colder than -39°C (-38°F) for more than 60 seconds. This is equal to more than 4.8 volts on the ECT sensor  2 signal circuit, as measured by the ECM.

DTCs P2184 and P2185 are Type B DTCs.

DTCs P2184 and P2185 are Type B DTCs.

An ECT sensor signal circuit or low reference circuit that is shorted to another 5-volt reference circuit can cause a DTC P2185 to set.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. Ignition ON, observe the ECT Sensor 2 parameter. The reading should be between -37 to +139°C (-35 to +282°F), depending on the current ambient temperature and the vehicle operating conditions.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the ECT sensor 2.
2. Ignition OFF for 90 seconds, test for less than 5 ohms of resistance between the low reference circuit terminal B and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, verify the scan tool ECT sensor 2 parameter is colder than -39°C (-40°F).

⇒	If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the ECM.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool ECT sensor 2 parameter is greater than 149°C (300°F)

⇒	If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

5. If all circuits test normal, test or replace the ECT sensor 2 .

Measure and record the resistance of the ECT sensor 2 at various ambient temperatures and compare those measurements to the Temperature vs. Resistance Table. Refer to Temperature Versus Resistance .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.