P2185

DTC P2184 or P2185

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P2184
- Engine Coolant Temperature (ECT) Sensor 2 Circuit Low Voltage

DTC P2185
- Engine Coolant Temperature (ECT) Sensor 2 Circuit High Voltage

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

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.

Conditions for Running the DTC

* The ignition is ON.
* DTC P2184 and P2185 run continuously within the enabling condition.

Conditions for Setting the DTC

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.

Action Taken When the DTC Sets

DTCs P2184 and P2185 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P2184 and P2185 are Type B DTCs.

Diagnostic Aids

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.

Circuit/System Verification

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.

Circuit/System Testing

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 A 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 B 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 B and the low reference circuit terminal A. 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.

Component Testing

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Engine Coolant Temperature Sensor Replacement
* Refer to Programming and Relearning for setup and programming. Programming and Relearning