P0597 Thermostat heater control circuit open

P0597 – OBD-II Trouble Code Technical Description

Thermostat heater control circuit open

What does the fault code mean P0597?

This P0597 diagnostic code applies to various makes and models of vehicles starting in 1996. It is connected to an electronically controlled engine thermostat. Although this is a general code, the steps to resolve it may vary depending on your specific vehicle. P0597, P0598 and P0599 relate to the electronically controlled engine thermostat and may apply to a variety of manufacturers including BMW, Mercedes, Audi, Mini, Volkswagen, Opel and Jaguar. This thermostat regulates engine temperature, which helps save fuel and reduce emissions and can also increase power. Code P0597 indicates a problem with the control voltage of this thermostat and may be caused by an open or shorted control circuit. P0597, P0598, and P0599 differ by vehicle brand, but are otherwise similar in nature and require similar steps to resolve.

Possible reasons

The P0597 code can have several potential causes. However, most often it is associated with problems in the electrical connector. Check it for corrosion or looseness. Otherwise, here's what else might cause this error:

1. Defective thermostat.
2. Leaking coolant.
3. Problems with the wiring between the thermostat and the control system.
4. Possibility of failure of the engine control computer (Motronic), although this is extremely rare and should be considered as a last resort after checking other possible causes.

Experience most often indicates that the problem is a loose or corroded electrical connector, or a problem with the electrically controlled thermostat itself. A coolant leak can also cause this error to appear. A Motronic computer failing is the least likely cause and should only be considered after the other components have been checked.

What are the symptoms of a fault code? P0597?

Code P0597 usually does not cause noticeable symptoms. In addition to the check engine light, you may notice abnormalities in your vehicle's temperature gauge readings. Depending on the position of the thermostat when it malfunctions, the temperature gauge may indicate either a higher or lower temperature than normal. However, if the thermostat fails when the engine is cold, it can cause the car to overheat. Unfortunately, the driver most likely won't notice anything unusual until it's too late.

Symptoms may vary depending on the position of the thermostat at the time of the problem, but in general, it will not cause significant changes in the vehicle's performance. The check engine light will come on and one of the above codes will be set. The temperature gauge may show abnormally high values ​​if the thermostat fails in the partially closed position, and conversely, it will show a lower temperature if the thermostat fails in the fully open position.

How to diagnose a fault code P0597?

To diagnose a P0597 problem, follow these steps:

1. Use an OBD-II scanner to confirm stored codes.
2. Check the electrical connector for visible problems such as corrosion.
3. Check the coolant level in the radiator, as low levels can cause the thermostat to overheat and set the code.
4. Remove the electrical connector and check the thermostat resistance.
5. Remove corrosion from the electrical connector using baking soda or a scraper. Then apply electrical grease and make sure the connection is tight.
6. Check the coolant level in the radiator, as low levels can cause an error and overheating of the electronic thermostat.
7. Check the resistance values ​​on the thermostat according to the service manual or information found on the Internet. This includes pin identification, wire color, and resistance values ​​at certain temperatures.
8. Use an infrared temperature sensor and a volt/ohmmeter to determine the engine temperature and check the voltage on the Motronic side according to the instructions.
9. If the voltage is within acceptable limits, continue diagnostics. If not, replace the Motronic unit.
10. Compare the resistance of the wires on the thermostatic side. If the resistance is outside the acceptable range, replace the thermostatic unit.

If the necessary tools and information are not available, it is recommended that you contact an auto repair shop that has the necessary equipment to perform the diagnosis.

Diagnostic errors

A common mistake when diagnosing a P0597 code is to immediately replace the entire electronic thermostat. While this can sometimes solve the problem, it is not always necessary to replace the entire thermostat. Sometimes the root of the problem lies in the system itself. Therefore, mechanics must be careful not only to repair corrosion on wires, but also to identify the source of that corrosion. It is likely that an engine coolant leak may be the source of the problem and requires immediate attention to avoid future recurrences of the error. Only careful analysis and diagnostics will allow you to accurately determine which part of the system should be repaired or replaced.

How serious is the fault code? P0597?

Code P0597 is not a serious threat to the driver's life, but it is important to the health of your vehicle. The thermostat controls the temperature of the engine, and if it is not working properly, it can cause serious problems. A faulty thermostat can cause the engine to overheat, which in turn can damage the engine and lead to costly repairs. Therefore, it is important to resolve this issue as soon as possible to avoid serious damage to your vehicle.

What repair will help eliminate the code? P0597?

The following common repairs can be made to resolve the P0597 code:

1. Cleaning or replacing damaged circuits: If corrosion or damage is found in electrical circuits, they should be cleaned or replaced.
2. Replacing the thermostat: If the thermostat has indeed failed, replacing this part may solve the problem.
3. Repairing a coolant leak: If a coolant leak is the source of the problem, it should be repaired and then the coolant level restored to normal.

The choice of specific repair depends on the source of the problem, and additional diagnostics may be required to accurately determine the problem.

What is P0597 Engine Code [Quick Guide]

P0597 – Brand-specific information

Code P0597 is a common diagnostic trouble code that applies to many makes of vehicles. It is connected to the electronically controlled engine thermostat. Although this code may be general, here are a few specific car brands that it may apply to and their meanings:

1. BMW: P0597 – Electronically controlled engine thermostat – open circuit.
2. Mercedes Benz: P0597 – Engine control thermostat B, failure.
3. Audi: P0597 – Electronic thermostat control open – open circuit.
4. Volkswagen: P0597 – Electronic thermostat control B – open circuit.
5. Mini: P0597 – Electronic thermostat control B failure.
6. Jaguar: P0597 – Electronically controlled engine thermostat – open circuit.
7. Opel: P0597 – Electronically controlled engine thermostat – open circuit.

Please note that the code may vary depending on the specific model and year of manufacture of the vehicle. It is also important to note that code P0597 may apply to other makes and models that use an electronically controlled engine thermostat. For accurate information on your vehicle make and model, it is recommended that you consult an authorized repair manual or consult an automotive mechanic.