Error Code P2440 is defined as Secondary Air Injection System Switching Valve Stuck Open Bank 1. This indicates a stuck open problem in the switching valve of the secondary air injection system in Bank 1.

This error code is a generic trouble code, meaning it applies to all vehicles equipped with the OBD-II system, especially those made since 1996 up to present. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.

Definition

The secondary air injection system helps reduce harmful pollutant emitted from the exhaust by pumping fresh air into the exhaust system. The PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) receives information from the secondary air injection system regarding the flow of the pressure. This information is then sent to the PCM through a voltage signal.

If the secondary air injection system sends voltage signal reading is outside the specifications of the manufacturer by at least 10%, the PCM will read that as a problem and will set the Error Code P2440.

Common Symptoms

As with other error codes, this code activates the Check Engine light and registers the code to the vehicle’s memory system. Other symptoms include:

  • Noisy secondary air injection system
  • Engine stalls while idle
  • Engine stalls when starting
  • Engine hesitates on acceleration

Possible Causes

There are many factors for this code to appear, some of the possible causes are:

  • Defective air injection valve
  • Defective air injection pump
  • Defective one-way check valve
  • Defective pressure sensor
  • Broken, frayed or shorted pressure sensor wiring
  • Broken, frayed or shorted vacuum switching valve wiring
  • Broken, corroded, or melted vacuum switching connector
  • Corroded or damaged pressure sensor connector
  • Bent pins in pressure sensor connector
  • Bent pins in the vacuum switching connector
  • Defective vacuum switching valve

How to Check

To diagnose this code, technicians use an OBD-II scanner to gather the freeze frame data and all the trouble codes stored in the PCM.

Next, they will check the vacuum switching valve wirings and look for signs of breakage, frays, or shorts.

Next, they check the vacuum switching valve connectors for damage, bent pins, or corrosion.

After fixing the problems above with repairs or replacement, technicians will then clear all the diagnostic trouble codes from the PCM and run the vehicle for a test drive to see if the code comes back.

Then, they check pressure sensor wirings for breakage, frays, or shorts.

Next, they check pressure sensor connector and look for signs of damage, bent pins, or corroded pins.

After fixing the problems above with repairs or replacement, technicians will then, they clear all the diagnostic trouble code from the PCM and run the vehicle for a test drive to see if the code comes back.

Next, they check the one-way check valve to make sure it’s working properly.

After fixing the problems above with repairs or replacement, technicians will then, they clear all the diagnostic trouble code from the PCM and run the vehicle for a test drive to see if the code comes back.

Next, they check the air injection pump to make sure it’s working properly, and look for signs of loose connections or breakage in the hoses.

Loose, breaks, etc., in the connection of air injection pump hoses must be repaired, if not replaced.

Next, they check the fuses of air injection system and look for signs of a blown fuse.

How to Fix

Since this code refers to faults or damages in individual components, these components must be repaired, if not replaced to fix the code. Typical repairs or replacement include:

  • Replacement of air injection valve
  • Replacement of one-way check valve
  • Replacement of air injection pump
  • Replacement of faulty pressure sensor
  • Repair or replacement of broken, frayed, or shorted pressure sensor wiring
  • Repair or replacement of corroded or damaged pressure sensor connector
  • Replacement of defective switching valve
  • Replacement of broken, frayed, or shorted vacuum switching valve wiring
  • Repair or replacement of corroded, or melted vacuum switching connector
  • Repair or replacement of bent pins in vacuum switching connection

One of the most overlooked aspects when diagnosing this code is the faulty one-way check valves, which is probably the most common cause of this code. Thus, it is important to check these to prevent misdiagnosis. Also, if the secondary air injection pump is replaced and the defective one-way check valves are not, that may cause damage to other components in the secondary air injection system.