P2189 Fault Code

System Too Lean at Idle Bank 2

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

The P2189 fault code indicates that the engine control module (ECM) has detected a lean condition in the air-fuel mixture at idle for Bank 2. This situation can lead to poor engine performance and increased emissions. A 'lean' condition occurs when there is insufficient fuel in the mixture or too much air, which can affect how efficiently the engine runs.

What are the symptoms of the P2189 code?

• Rough or unstable idle, especially when the engine is cold.
• Engine hesitation or stalling when accelerating or at idle.
• Decreased fuel efficiency due to improper air-fuel mixture.
• Possible check engine light (CEL) illumination.

What causes the P2189 code?

• Insufficient fuel supply from the fuel injectors or fuel pump.
• Air leaks in the intake system, such as broken hoses or gaskets.
• Faulty mass air flow (MAF) or manifold absolute pressure (MAP) sensors.
• A malfunctioning oxygen sensor may incorrectly read the oxygen levels, causing the ECM to adjust the fuel mixture improperly.
• Fuel quality issues or fuel filter blockages could also contribute to this fault code.

How to fix P2189?

• Inspect and repair any vacuum leaks in the intake system.
• Test the fuel injectors and fuel pump to ensure they are providing adequate fuel supply.
• Check and, if necessary, replace the MAF or MAP sensors.
• Inspect and consider replacing the oxygen sensor if it is found to be faulty.
• Ensure that the fuel quality is acceptable and replace the fuel filter if it is clogged.