The P0640 trouble code indicates a malfunction in the intake air heater control circuit. This circuit is responsible for controlling the intake air heater, which helps warm the air entering the engine for improved combustion efficiency, particularly during cold weather conditions.
P0640 Intake Air Heater Control Circuit
Code symptoms P0640.
1. Check Engine Light (CEL) is illuminated on the dashboard.
2. Decreased engine performance, especially during cold starts.
3. Rough idling or stalling, especially when the engine is cold.
4. Increased fuel consumption.
5. Possible emissions issues.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0640.
1. Faulty intake air heater relay.
2. Defective intake air heater element.
3. Wiring issues such as short circuits or open circuits in the intake air heater control circuit.
4. Corrosion or poor connections in the wiring harness or connectors associated with the intake air heater circuit.
5. Malfunctioning Engine Control Module (ECM) or Powertrain Control Module (PCM), although this is rare.
Code Solutions P0640.
1. Inspect the intake air heater relay and replace it if it’s found to be faulty.
2. Check the intake air heater element for continuity using a multimeter and replace it if it’s defective.
3. Inspect the wiring harness and connectors in the intake air heater control circuit for any signs of damage, corrosion, or loose connections. Repair or replace any damaged components as necessary.
4. Perform a thorough visual inspection of the intake air heater system to check for any obvious issues.
5. Clear the trouble codes and perform a test drive to verify that the issue has been resolved. If the code persists, further diagnosis may be required.