For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0217: Engine Coolant Over Temperature

### Circuit Description

The engine control module (ECM) monitors the temperature of the engine coolant for engine control and as an enabling criteria for some diagnostics. The amount of air flow into an engine is proportional to the amount of heat an engine generates. The ECM monitors the amount of air flow into the engine to calculate engine coolant temperature (ECT). The ECM uses the calculated temperature to determine if the engine has warmed up to the thermostat regulating temperature. If the coolant temperature does not increase normally, does not reach the regulating temperature of the thermostat, or goes over the thermostat regulating temperature, diagnostics that use the ECT as enabling criteria may not run when expected.

### Conditions for Running the DTC

• | DTCs P0031, P0032, P0107, P0108, P0110, P0111, P0112, P0113, P0116, P0117, P0118, P0122, P0123, P0125, P0313, P0132, P0133, P0134, P0135, P0217, P0300, P0313, P0324, P0340, P0444, P0445, P0496, P0502, P0506, P0507, P0562, P0563, P0606, P2110, P2610, and U0101 are not set.

• | The engine has been OFF for more than 6 hours.

| OR

| The start-up engine coolant temperature (ECT) is less than 45°C (113°F).

• | The engine is running.

• | The engine has been at an idle state for 100-600 seconds.

• | The ECT is greater than 50°C (122°F).

• | The intake air temperature (IAT) is more than 35°C (95°F).

• | The airflow into the engine is less than 45 g/s or the calculated airflow into the engine is less than 43 g/s. If the ECM detects that the airflow into the engine is more than 45 g/s or 43 g/s after the diagnostic runs for 10 seconds, the ECM will not report a pass or fail.

• | This DTC runs once per ignition cycle once the above conditions are met.

### Conditions for Setting the DTC

The ECM detects that the engine coolant temperature is greater than 110°C (230°F).

### Action Taken When the DTC Sets

DTC P0217 is a Type B DTC.

### Conditions for Clearing the MIL/DTC

DTC P0217 is a Type B DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running, observe the DTC information with a scan tool. Verify that DTC P0480 and P0481 is not set.

⇒ | If any of the DTCs are set, refer to DTC P0480 or P0481.

2. Observe the DTC information with a scan tool. DTC P0217 should not set.
3. Perform the Loss of Coolant to verify correct fluid level.
4. Perform the Thermostat Diagnosis to verify correct normal operating temperature.
5. Perform the Symptoms - Engine Cooling to verify the correct operation of the cooling fans.
6. 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.
7. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. 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. Ignition ON, clear the DTC information with a scan tool.
3. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit termiinal 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.

4. Ignition ON, verify the ECT sensor parameter is at -40°C (-40°F).

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

5. Ignition ON, clear the DTC information with a scan tool.

Important: If the signal circuit is shorted to voltage the ECT sensor may be damaged.

6. Install a 1A fused jumper wire between the signal circuit termiinal A and the low reference circuit termiinal B. Verify the scan tool ECT sensor parameter is greater than 128°C (262°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.

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

### Component Testing

1. Ignition OFF, disconnect the harness connector at the ECT sensor.

Important: A thermometer can be used to the used to test the sensor off the vehicle.

2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature Versus Resistance table and verify that the resistance is within 5 percent of the specification.

⇒ | If not within the specified range, replace the ECT sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Engine Coolant Temperature Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming