What are the common causes of P2059?

An open in the reductant injection air pump control circuit. A failed reductant injection air pump. A failed reductant injection air pump control module. Water intrusion in the pump connector.

Command the reductant injection air pump with a scan tool. Test the pump control circuit for an open. Check the pump connector for water intrusion. Test the pump motor for operation. Replace the reductant injection air pump or control module if faulty. Clear the code and retest.

P2059

Reductant Injection Air Pump Control Circuit/Open

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P2059 means Reductant Injection Air Pump Control Circuit/Open.

Where it lives

For P2059, the circuit described runs through the pump. The description of P2059 reports the pump as open.

Check these first

An open in the reductant injection air pump control circuit
A failed reductant injection air pump
A failed reductant injection air pump control module
Water intrusion in the pump connector

What to do next

Command the reductant injection air pump with a scan tool
Test the pump control circuit for an open
Check the pump connector for water intrusion
Test the pump motor for operation
Replace the reductant injection air pump or control module if faulty
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.