P0490 Fault Code

Exhaust Gas Recirculation Control Circuit Low

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0490 fault code indicates that the Exhaust Gas Recirculation (EGR) control circuit is operating at a low level, which can lead to inefficient engine performance and increased emissions. The EGR system is responsible for recirculating a portion of the exhaust gases back into the intake manifold to reduce nitrogen oxide emissions and improve efficiency.

What are the symptoms of the P0490 code?

Symptoms of a P0490 fault code can vary but generally include:

• Illuminated check engine light
• Rough idle or poor engine performance
• Increased emissions during vehicle operation
• Decreased fuel efficiency
• Potential engine overheating due to improper combustion.

What causes the P0490 code?

Common causes of the P0490 code may include a faulty EGR valve, damaged wiring or connectors related to the EGR circuit, clogged passages in the EGR system, or an issue with the engine control module (ECM) itself. Environmental factors such as carbon buildup can also contribute to this problem.

How to fix P0490?

To resolve the P0490 code, a mechanic may begin by inspecting the EGR valve for proper operation and ensuring it is not stuck open or closed. Checking the wiring and connectors for any signs of damage or corrosion is also important. Cleaning any carbon deposits from the EGR system and manifold can help restore function. If necessary, replacing the EGR valve or reprogramming the ECM may be needed to fix the issue permanently.