Spark

DTC P0597-P0599

The engine control module (ECM) controls the pulse width modulated (PWM) thermostat. The thermostat controls coolant flow and regulates the engine operating temperature. Ignition voltage is supplied directly to the thermostat. The ECM controls the thermostat by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.

P0597-P0599 (Without FX3)

P0598 or P0599 (FX3)

P0597 (Without FX3)

The ECM detects a short circuit to voltage on the thermostat heater control circuit.

P0598 (Without FX3)

The ECM detects a short circuit to ground on the thermostat heater control circuit.

P0598 (FX3)

The ECM detects an open or a short circuit to ground on the thermostat heater control circuit.

P0599 (Without FX3)

The ECM detects an open/high resistance on the thermostat heater control circuit.

P0599 (FX3)

The ECM detects a short circuit to voltage on the thermostat heater control circuit.

DTC P0597, P0598, and P0599 are Type C DTCs.

DTC P0597, P0598, and P0599 are Type C DTCs.

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

Cooling Fan Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, verify that the DTC P0597, P0598, or P0599 is not set.

⇒	If a DTC is set, perform the Circuit/System Testing.

2. 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.

1. Ignition OFF, disconnect the harness connector at the E41 Engine Coolant Thermostat Heater.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.

3. Ignition ON, test for less than 5 V between the control circuit terminal 2 and ground.

⇒	If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Ignition OFF, test for greater than 10Ω between the control circuit terminal 2 and ground.

⇒	If less than the specified range, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 1 and the control circuit terminal 2.

⇒	If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

Note: The thermostat heater is not serviceable, replace the thermostat as an assembly if necessary.

6. If all circuits test normal, test or replace the thermostat.

Note: The thermostat heater is not serviceable, replace the thermostat as an assembly if necessary.

1. Ignition OFF, disconnect the harness connector at the E41 Engine Coolant Thermostat Heater.
2. Test for 10-20 Ω between the ignition terminal 1 and the control terminal 2.

⇒	If not within the specified range, replace the thermostat.

3. Test for infinite resistance between the circuits of the E41 Engine Coolant Thermostat Heater and the housing.

⇒	If not the specified range, replace the thermostat.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.