Skip the auto shop - Our mechanics make house calls

P2059 OBD-II Trouble Code: Reductant Injection Air Pump Control Circuit/Open

Check Engine Light

P2059 code definition

Reductant Injection Air Pump Control Circuit/Open

What the P2059 code means

P2059 is an OBD-II generic code indicating that the Engine Control Module (ECM) detects that the reductant injection air pump control circuit has an open in the circuit.

What causes the P2059 code?

  • The ECM controls the reductant injection air pump. The ECM can detect open circuits or high resistance in the control circuit and will turn on the Check Engine Light if it detects a fault.

  • A broken wire in the control circuit from the ECM to the reductant injector air pump.

What are the symptoms of the P2059 code?

  • The Check Engine Light will be illuminated and the code set in ECM memory as a fault.

  • The exhaust emission may be richer than expected.

  • The vehicle will fail any emission tests due to the Check Engine Light being on.

How does a mechanic diagnose the P2059 code?

  • Scans and documents the codes in the ECM; looks at the corresponding freeze frame data for failure

  • Checks the air pump wiring connections for problems with loose or corroded connections

  • Checks the air pump for the proper resistance

  • Follows the manufacturer pinpoint tests for the diagnosis and replacement of the reductant injector and air pump

Common mistakes when diagnosing the P2059 code?

  • Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired.

  • Failing to clear the ECM codes after the codes are fixed so the ECM will enable the system to normal again.

How serious is the P2059 code?

Code P2059 is a code that may not cause any drive complaints but will put on the Check Engine Light and cause a vehicle to fail an emission test.

What repairs can fix the P2059 code?

Additional comments for consideration regarding the P2059 code

Code P2059 is for an open circuit for the reductant injector air pump. This is a code only used by a couple of different manufacturers; meanings may be different from your vehicle than this article implies. Follow the pinpoint test for the vehicle you are working on to determine if your vehicle uses the reductant injection system. In some vehicles, this code is used for O2 sensor problems.

Need help with a P2059 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
How to Transfer a Car Title in Idaho
In order to prove ownership of a car, you must have the title. However, when a car is sold, given away or inherited, the title needs...
How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...

Related questions

Q: Timing chain problem?

It could very well be a timing chain problem. The P0016 and 17 indicate that the camshaft sensors are sensing the camshaft in a position that does not logically correspond with the crankshaft. The P0302 and P0355 codes are misfire...

Q: Transmission replaced, but still slipping - 2009 Kia Borrego

There's a lot going on here. As far as the transmission concerns, your repair should be under warranty since you had the work done at the dealer. For the rest of the concerns, you may want to hire another technician...

Q: The truck starts then stalls or shuts off

This could be a wide variety of potential issues ranging from a vacuum leak, bad idle air control valve, low fuel pressure, bad coil packs, or many other possibilities. When this happens you should have a Check Engine Light on...