Description of the P0655 fault code.
OBD2 Error Codes

P0655 Engine Overheat Indicator Circuit Malfunction

26.05.2022 /

P0655 – OBD-II Trouble Code Technical Description

Trouble code P0655 is a general trouble code that indicates a malfunction in the engine overheat indicator control circuit.

What does the fault code mean P0655?

Trouble code P0655 indicates a problem with the engine overheat indicator control circuit. This means that the control engine module (PCM) or other control modules in the vehicle have detected abnormal voltage in the circuit responsible for controlling the engine overheat indicator. Low or high voltage can indicate a variety of problems in the system, such as a faulty engine temperature sensor, wiring or connection problems, or even a faulty control module itself.

Fault code P0655.

Possible reasons

Several possible reasons that could cause this P0655 trouble code:

  • Faulty engine temperature sensor: If the engine temperature sensor fails or produces incorrect signals, it can cause the P0655 code to appear.
  • Wiring and connections: Poor connections, corrosion or breaks in the wiring between the engine temperature sensor and the control module can cause incorrect readings and an error.
  • Engine control module (PCM) malfunction: If the PCM, which controls engine functions, has a malfunction or malfunction, this can also cause the P0655 code to appear.
  • Power problems: Intermittent or insufficient power to the vehicle's electrical system can cause the temperature sensor or PCM to not operate properly, which can cause P0655.
  • Malfunction of the engine overheat indicator: The engine overheat indicator itself may be faulty, causing the information to be displayed incorrectly and causing an error to occur.

To accurately identify the cause, it is recommended to carry out diagnostics using appropriate equipment or contact a qualified auto mechanic.

What are the symptoms of a fault code? P0655?

Symptoms when trouble code P0655 is present may vary depending on the specific cause and context:

  • Engine overheat indicator on the dashboard: If the problem is due to an erroneous engine overheat light, you may notice that the light remains on or flashes even if the engine is not overheated.
  • Unstable engine operation: Incorrect reading of engine temperature can result in engine instability such as shuddering, rough idling, or even possible acceleration problems.
  • Degraded performance and fuel economy: If engine temperature data is incorrect, the PCM may adapt the fuel mixture and ignition timing to incorrect conditions, which may result in poor engine performance and fuel efficiency.
  • Limiting engine operating modes: Some vehicles may enter limp mode or limit engine operation if severe engine temperature problems occur, which may be caused by the P0655 code.
  • Increased fuel consumption: If the engine management system is in limp mode due to erroneous temperature data, it may result in increased fuel consumption.

How to diagnose a fault code P0655?

Diagnosing the P0655 trouble code involves a number of steps to identify the cause of the problem, some of them are:

  1. Checking the error code: You must first use a diagnostic scanner to read the P0655 error code and any additional error codes that may be associated with it.
  2. Visual inspection: Inspect the wiring and connections associated with the engine temperature sensor and PCM for damage, corrosion, or breaks.
  3. Checking the engine temperature sensor: Using a multimeter, check the resistance of the engine temperature sensor at different temperatures. The values ​​must comply with the manufacturer's specifications.
  4. Electrical circuit check: Check the voltage and resistance in the circuit between the engine temperature sensor and the PCM to ensure that the wiring and connections are OK.
  5. Check PCM: Check the PCM for errors and diagnose its operation to rule out the possibility of a control module malfunction.
  6. Checking the engine overheat indicator: Check the engine overheat indicator itself for correct operation and connection.
  7. Checking Additional Components: In some cases, other components of the engine management system, such as relays, fuses, or additional sensors, may be the cause of the P0655 code.

After all the above checks have been carried out and the cause of the problem has been identified, the necessary repairs or replacement of components should be carried out. If you are unsure of your diagnostic and repair skills, it is recommended that you contact a qualified auto mechanic or auto repair shop.

Diagnostic errors

When diagnosing DTC P0655, the following errors may occur:

  • Incorrect interpretation of error code: Sometimes mechanics or vehicle owners may misinterpret the meaning of the P0655 code, which can lead to incorrect diagnosis and repair.
  • Faulty engine temperature sensor diagnosis: If the engine temperature sensor is not tested or is not tested correctly, this can lead to misdiagnosis and sensor replacement when the problem may be in the wiring or the PCM itself.
  • Skipping electrical circuit diagnostics: Sometimes mechanics may skip checking the electrical circuit between the temperature sensor and the PCM, which can lead to an incorrect diagnosis and repair.
  • Ignoring other error codes: It is possible that P0655 is a result of other problems, and there may be additional error codes that also need to be diagnosed and repaired.
  • Faulty component replacement: Mixing up or incorrectly replacing components, such as the temperature sensor, without performing a full diagnosis can result in unnecessary repair costs.
  • Incorrectly correcting electrical problems: If wiring or connections are not checked correctly or completely, it may result in missing the source of the problem and causing incorrect repairs.

To avoid these errors, it is important to follow the diagnostic process and perform tests using the correct equipment and tools.

How serious is the fault code? P0655?

Trouble code P0655 can be serious, especially if it goes undetected and not repaired in a timely manner, there are several aspects that make this code potentially serious:

  • Potential engine damage: If the P0655 temperature sensor problem is not resolved, it can cause the engine to overheat, which can ultimately cause severe engine damage or even engine failure.
  • Performance degradation and fuel consumption: Improper control of the fuel and ignition system caused by erroneous engine temperature data can result in poor engine performance and increased fuel consumption.
  • Limiting engine operating modes: In some cases, if the P0655 temperature sensor problem remains unresolved, the engine management system may enter limp mode, which will limit engine operation and may result in loss of power or complete vehicle stall.
  • Increased operating costs: Ignoring trouble code P0655 may result in increased costs for repairs or replacement of engine management system components in the future.

Overall, although the P0655 trouble code is not always associated with catastrophic consequences, undetected and unresolved problems can lead to serious engine and ride safety problems. Therefore, it is recommended that diagnosis and repair be carried out as soon as possible after this code appears.

What repair will help eliminate the code? P0655?

The repair that will resolve the P0655 trouble code depends on the specific cause of the code, but some possible remedies include:

  1. Replacing the engine temperature sensor: If the problem is related to a malfunction of the engine temperature sensor itself, then it is necessary to replace it with a new one that meets the manufacturer's specifications. After replacing the sensor, it is recommended to run diagnostics to ensure that the P0655 code no longer appears.
  2. Repair or replacement of wiring and connections: If the problem is an open, corroded, or poor connection in the wiring between the temperature sensor and the PCM, the associated wires and connectors will need to be repaired or replaced.
  3. PCM diagnostics and repair: In some cases, the cause of the P0655 code may be due to a problem with the PCM itself. In this case, diagnostics and, if necessary, repair or replacement of the control engine module may be required.
  4. Checking and replacing other components: In some cases, the problem may be caused by other components of the engine management system, such as relays, fuses, or additional sensors. After diagnosing and identifying the cause of the malfunction, they may require repair or replacement.
  5. PCM Software Update: In rare cases, the problem may be related to the PCM software. In this case, the car manufacturer may release a firmware update that will help fix the problem.

It is important to perform diagnostics to accurately determine the cause of the P0655 code before performing any repair work. To do this, it is better to contact a qualified auto mechanic or car service center.

What is P0655 Engine Code [Quick Guide]

P0655 – Brand-specific information

Trouble code P0655 indicates a problem with the engine overheat indicator control circuit. Here is a transcript and examples of using this error code for some well-known car brands:

These are just some examples of how the P0655 code may appear on different makes of vehicles. Like all trouble codes, its meaning may vary depending on the specific model and context.

Add a comment