P0640 Intake air heater control circuit malfunction

P0640 – OBD-II Trouble Code Technical Description

Trouble code P0640 indicates a problem with the intake air heater electrical circuit.

What does the fault code mean P0640?

Trouble code P0640 indicates a problem with the intake air heater circuit. This means that the powertrain control module (PCM) has detected that the intake air heater control circuit voltage is not within manufacturer specifications.

Possible reasons

Some possible reasons for the P0640 trouble code:

• Intake air heater malfunction: Problems with the heater itself, such as open circuits or short circuits.
• Damaged or broken electrical wiring: The wires connecting the intake air heater to the PCM may be damaged or broken.
• Malfunctioning PCM: Problems with the powertrain control module itself can cause P0640.
• Problems with sensors or air flow sensors: Problems with other parts of the air intake system can cause the P0640 code to erroneously trigger.
• Circuit Overload: High voltage in the intake air heater circuit may be caused by an overload or short circuit.
• Grounding Issues: Insufficient electrical system grounding can also be a cause of the P0640 code.

What are the symptoms of a fault code? P0640?

Some typical symptoms that may occur when the P0640 trouble code appears:

• Check Engine Light: When a P0640 code appears, the Check Engine light on your vehicle's dashboard may illuminate, indicating there is a problem with the system.
• Loss of Power: If the intake air heater malfunctions, you may experience a loss of engine power due to insufficient heating of the intake air, especially when operating at low temperatures.
• Unstable idle speed: The vehicle may experience instability in idle speed due to improper operation of the intake air control system.
• Poor Fuel Economy: If the intake air heater malfunctions, fuel economy may deteriorate due to insufficient combustion efficiency.

How to diagnose a fault code P0640?

The following steps are recommended to diagnose DTC P0640:

1. Checking the Check Engine indicator: First, you should check to see if there is a Check Engine light on your dashboard. If the light comes on, this may indicate a problem with the air intake system.
2. Using the Diagnostic Scanner: Connect the diagnostic scanner to the vehicle's OBD-II port and read the trouble codes. Verify that the P0640 code is indeed present in the control module memory.
3. Checking the Intake Air Heater Control Circuit: Check the electrical circuit related to the intake air heater. This includes checking the wiring, connectors, and the heater itself for corrosion, breaks, or shorts.
4. Using a multimeter: Use a multimeter to check the voltage on the intake air heater control circuit. The voltage must be within the manufacturer's specifications.
5. Checking the intake air heater: Check the intake air heater itself for damage or malfunction. Replace it if necessary.
6. Checking other intake system components: Check other air intake system components such as sensors and valves to make sure there are no other problems that could be causing the P0640 code.
7. Determining and eliminating the cause: After locating the source of the problem, carry out the necessary repairs or replace the faulty components.
8. Clearing the error code: After troubleshooting, use a diagnostic scan tool to clear the error code from the control module memory.

Diagnostic errors

When diagnosing DTC P0640, the following errors may occur:

• Incorrect interpretation of code: Sometimes mechanics may misinterpret the P0640 code and start diagnosing the wrong component or system.
• Insufficient wiring check: Some mechanics may skip checking the wiring and connectors in the intake air heater control circuit, which may result in missing the problem.
• Incorrect component replacement: Instead of thoroughly diagnosing and finding the root cause of the problem, mechanics may incorrectly replace components, which can lead to additional costs and malfunctions.
• Skip checking other components: Sometimes mechanics may focus on only one component related to the intake air heater and skip checking other components of the intake system.
• Misinterpretation of test results: Sometimes test or measurement results can be misinterpreted, which can lead to incorrect conclusions about the condition of the air intake system.

To avoid these errors, it is important to follow professional diagnostic techniques, thoroughly inspect all components and systems associated with the intake air heater, and be attentive to each diagnostic step.

How serious is the fault code? P0640?

Trouble code P0640 can be serious depending on your specific situation and the condition of your vehicle. Several factors that may influence the severity of this code:

• Impact on performance: The intake air heater can affect engine performance, especially on cold days. If the heater is faulty or not working, it can cause the engine to start poorly, run rough, and other problems.
• Release of harmful substances: Some vehicles use an intake air heater to reduce emissions. Failure of this device may result in increased emissions and negative impacts on the environment.
• Work in extreme conditions: In some climates, especially cold temperatures, the intake air heater may be critical to proper engine operation. Failure of this component may render the vehicle unusable in certain conditions.
• Potential damage to other components: A malfunctioning intake air heater can cause the engine or other components to overheat, which can ultimately damage the engine or other vehicle systems.

Overall, an intake air heater fault indicated by a P0640 code requires careful attention and immediate repair to prevent further problems with the engine and other vehicle systems.

What repair will help eliminate the code? P0640?

To resolve DTC P0640, follow these steps:

1. Checking wiring and connections: The first step is to check the condition of the wiring and connections associated with the intake air heater. Make sure all wires are intact and securely connected to the appropriate terminals.
2. Checking the heater itself: The next step is to check the intake air heater itself for damage or corrosion. If necessary, replace the heater with a new one.
3. Checking sensors and temperature sensors: Check the operation of the temperature sensors and their connections. Incorrect operation of these sensors can also cause P0640.
4. Checking the Engine Control Module (ECM): Check the status of the engine control module and its software. The module may require reprogramming or replacement.
5. Clearing errors and rechecking: After completing all the above steps, clear the errors using the diagnostic scanner. After this, re-check the car for errors to ensure that the problem is resolved.

If you are not experienced in car repairs, it is recommended that you have a qualified auto mechanic or auto repair shop perform these steps. Improper repairs can lead to additional problems or damage to the vehicle.

What is P0640 Engine Code [Quick Guide]

P0640 – Brand-specific information

Trouble code P0640 refers to the intake air heater control system, meaning for some specific car brands:

• Volkswagen (VW): Intake manifold heater voltage is insufficient.
• Ford: Insufficient or excessive voltage in the intake manifold heater control circuit.
• Chevrolet: Insufficient or excessive voltage in the intake manifold heater control circuit.
• BMW: Intake manifold heater failure.
• Toyota: Insufficient or excessive voltage in the intake manifold heater control circuit.

Each manufacturer may use its own terms and descriptions for trouble codes, so it is recommended that you refer to the repair and service documentation for your specific vehicle make and model for more accurate information.