P2440 OBD-II Trouble Code: Secondary Air Injection System Switching Valve Stuck Open Bank 1

Check Engine Light

P2440 code definition

The P2440 diagnostic trouble code is an indication that the Powertrain Control Module (PCM) has detected that the switching valve of the secondary air injection system is stuck open on Bank 2.

Related Trouble Codes

  • P2441 OBD-II Trouble Code: Secondary Air Injection System Switching Valve Stuck Closed Bank 1

  • P2442 OBD-II Trouble Code: Secondary Air Injection System Switching Valve Stuck Open Bank 2

  • P2443 OBD-II Trouble Code: Secondary Air Injection System Switching Valve Stuck Closed Bank 2

What the P2440 code means

The purpose of the secondary air injection system is to pump fresh air into the exhaust system. This reduces the amount of harmful pollutants that are emitted by the exhaust. The PCM receives information from the secondary air injection system regarding pressure and flow. This information is sent to the PCM through a voltage signal.

If the secondary air injection system sends a voltage signal reading to the PCM that exceeds the manufacturer’s specifications by at least ten (10) percent, the P2440 diagnostic trouble code will be stored and the Check Engine Light will come on.

What causes the P2440 code?

  • Faulty air injection valve
  • Faulty one-way check valve
  • Faulty air injection pump
  • Faulty pressure sensor
  • Pressure sensor wiring that is frayed, broken, or shorted
  • Pressure sensor connector that is damaged or corroded
  • Pressure sensor connector that has bent pins
  • Faulty vacuum switching valve
  • Vacuum switching valve wiring that is frayed, broken, or shorted
  • Vacuum switching connector that is broken, melted, corroded
  • Vacuum switching connector that has bent pins

What are the symptoms of the P2440 code?

  • Check Engine Light is on
  • Secondary air injection system may be noisy
  • Engine may stall when idling
  • Engine may stall when starting the vehicle
  • Engine may hesitate when accelerating
  • P2440 diagnostic trouble code stored in the PCM

How does a mechanic diagnose the P2440 code?

  • Uses an OBD-II scanner to collect freeze frame data and all the trouble codes that have been stored by the PCM.

  • Inspects vacuum switching valve wiring for frays, breaks, and shorts.

  • If any vacuum switching valve wiring has frays, breaks, and shorts, repair and replace as required.

  • Inspect vacuum switching valve connector for damage, corrosion, or bent pins.

  • If the vacuum switching valve connector is damaged, corroded, or has a bent pin, repair and replace as required.

  • Clears all diagnostic trouble codes from the PCM and operates the vehicle or completes a test drive to see if the P2440 trouble code comes back

  • Inspects pressure sensor wiring for frays, breaks, and shorts.

  • If any pressure sensor wiring has frays, breaks, and shorts, repair and replace as required.

  • Inspects pressure sensor connector for damage, bent pins, and corrosion.

  • If the pressure sensor connector is damaged, corroded, or has bent pin, repair and replace it as required.

  • Clears all diagnostic trouble codes from the PCM and operates the vehicle or completes a test drive to see if the P2440 trouble code comes back.

  • Inspects the one-way check valve to ensure it is working properly.

  • If one-way check valves are faulty, repair and replace them required.

  • Clears all diagnostic trouble codes from the PCM and operates the vehicle or completes a test drive to see if the P2440 trouble code comes back.

  • Clears all diagnostic trouble codes from the PCM and operates the vehicle or completes a test drive to see if the P2440 trouble code comes back.

  • Inspects the air injection pump to ensure it is working properly.

  • Inspects the air injection pump hoses for breaks and loose connections.

  • If there are breaks and/or loose connection in the air injection pump hoses, repair or replace as required.

  • Inspects the air injection system fuses.

  • If there is damaged wiring or pumps that are causing a blown fuse, repair or replace them as required.

Common mistakes when diagnosing the P2440 code

In most cases, the P2440 diagnostic trouble code is caused by faulty one-way check valves. Therefore, it is important to test them to prevent a misdiagnosis and multiple secondary air injection pump replacements. It is also important to add a drain tube onto the pump housing when replacing the secondary air injection pump, as failing to do so could cause multiple secondary air injection pump failures in the future.

How serious is the P2440 code?

When the P2440 diagnostic trouble code is stored by the PCM the vehicle may stall out or hesitate during operation, and driving under these conditions is dangerous. For this reason, the P2440 trouble code is considered serious and should diagnosed and repaired as soon as possible.

What repairs can fix the P2440 code?

  • Replace faulty air injection valve
  • Replace faulty one-way check valve
  • Replace faulty air injection pump
  • Replace faulty pressure sensor
  • Repair or replace frayed, broken, or shorted pressure sensor wiring
  • Repair or replace damaged or corroded pressure sensor connector
  • Replace faulty switching valve
  • Repair or replace frayed, broken, or shorted vacuum switching valve wiring
  • Repair or replace melted, corroded vacuum switching connector
  • Repair or replace bent pins in the vacuum switching connector

Additional comments for consideration regarding the P2440 code

Faulty one-way check valves are often overlooked when diagnosing the P2440 diagnostic trouble code. Faulty one-way check valves are a common cause of this code so it is important to check them in order to prevent misdiagnosis. If the secondary air injection pump is replaced and faulty one-way check valves are not, this could cause damage to other components of the secondary air injection system.

Need help with a P2440 code?

YourMechanic offers certified 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

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