Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means there's a problem with the part of the car that helps warm up the air going into the engine, especially when it's cold outside. It's like when a heater in your house doesn't work properly.
The intake air heater is used to warm the air entering the engine to improve combustion efficiency, especially in cold conditions. This code indicates an issue with the electrical circuit that controls this heater.
The P0640 code is triggered when the Engine Control Module (ECM) detects a malfunction in the intake air heater control circuit. This could be due to an open or short circuit, or a failure in the heater relay or the heater itself.
• Check Engine Light is on
• Poor engine performance in cold weather
• Increased emissions
• Faulty intake air heater
• Damaged wiring or connectors
• Failed intake air heater relay
ECM: Engine Control Module, the computer that controls the engine's functions.
Intake Air Heater: A device that warms the air entering the engine to improve combustion efficiency.
• Scan the vehicle for codes and freeze frame data
• Inspect the intake air heater and its wiring for damage
• Test the intake air heater relay for proper operation
• Replace the intake air heater if faulty
• Repair or replace damaged wiring or connectors
• Replace the intake air heater relay if necessary
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Dodge Ram
• Ford F-Series
• Chevrolet Silverado
• Regularly inspect and maintain the intake air heater
• Keep electrical connections clean and secure
• Perform routine engine diagnostics
Sensor Issue
• Have the vehicle inspected by a professional if the Check Engine Light is on
• Avoid driving in extremely cold conditions until repaired
Check with the vehicle manufacturer for warranty coverage on emission-related components.
The P0640 code has been more prevalent in diesel engines where intake air heaters are commonly used to aid cold starts.
Moderate – While the vehicle may still be operable, performance and emissions can be affected, especially in cold weather.
Driving with this code may lead to increased emissions, which could be a violation of local environmental regulations.
• Engine at operating temperature
• Cold ambient temperatures
The intake air heater is typically located in the air intake system, near the air filter or throttle body.
Q: Can I drive with a P0640 code?
A: While you may be able to drive, engine performance may be reduced, especially in cold weather. It's best to have it checked soon.
Q: What happens if I ignore the P0640 code?
A: Ignoring the code can lead to poor engine performance, increased emissions, and potential damage to the engine over time.
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