P2059 Fault Code

Reductant Injection Air Pump Control Circuit/Open

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

The P2059 fault code indicates a problem with the reductant injection air pump control circuit. This circuit may be open or shorted, resulting in inadequate performance of the reductant system in diesel vehicles equipped with selective catalytic reduction (SCR) systems. This can lead to increased emissions and may cause the vehicle to fail emissions tests.

What are the symptoms of the P2059 code?

Drivers may experience various symptoms related to this fault code, such as:

• Warning lights illuminated on the dashboard, such as the check engine light.
• Poor engine performance or reduced power output when accelerating.
• Increased emissions or failure to meet emission standards.
• Potential limitation on driving range due to SCR system malfunction.

What causes the P2059 code?

Several factors can lead to a P2059 code, including:

• A malfunctioning reductant injection air pump, which may be unable to create the necessary pressure.
• Damaged wiring or connectors in the control circuit, which could interrupt electrical signals.
• Faulty control module settings that fail to activate the air pump.
• Blockages or leaks in the reductant system that prevent proper operation.

How to fix P2059?

To address the P2059 fault code effectively, consider the following steps:

• Inspect the reductant injection air pump and its electrical connections for any visible damage or wear.
• Test the wiring and connectors in the control circuit for shorts or opens, and repair or replace as necessary.
• If the air pump is defective, replace it with a new unit and clear any existing fault codes from the vehicle's ECU.
• Ensure that all components of the reductant system, including the injector and tank, are functioning properly.