OBD-II P0410 Trouble Code
Secondary Air Injection System Malfunction
Here is what a P0410 means, in simple terms
P0410 is an OBD-II generic code. A P0410 is set whenever an engine's control computer (ECC) detects a fault with the air injection system. The air injection system (AIS) is designed to supply air to the engine exhaust as it exits the exhaust manifold. Injection points may be at the exhaust manifold, before the catalytic converter (CAT) or mid-way through the CAT. The operation involves introducing oxygen to the exhaust, allowing for any remaining fuel to continue combustion. The AIR system exists to prompt emissions reduction. The ECC determines whether or not to trigger the P0410 code based on data from the oxygen sensor(s) and/or when an electrical break occurs within the air pump circuitry. When using oxygen sensor data to test the air injection system, the ECC commands the air pump on and measures oxygen sensor data for a drop in voltage (indication that the exhaust is now lean due to the introduction of unmetered air). When the ECC does not realize a drop in O2 voltage, it triggers a P0410.
What caused my vehicle to set a P0410 trouble code?
There a few components which make up the secondary air injection system. We'll start with the main component which is the air pump. The air pump may be mechanically operated (serpentine belt) or electrical. The second component is the diverter valve, which is attached to the air pump's outlet and controls whether air should be delivered to the exhaust or atmosphere. Third is the air injection system control solenoid which triggers the diverter valve open or closed, and finally we have the air tube and check valve, located between the diverter valve and the exhaust manifold. The check valve is used to allow air flow in only one direction; toward the exhaust and away from the pump. Note, some of these components may be combined into single units such as in the case of a single unit check valve/diverter valve. Trouble with any one or more of the air injection components mentioned above will set a P0410. Common P0410 triggering reasons include:
- The air injection pump motor is defective.
- The air injection pump motor fuse is blown. Locate fuse panel. Identify air injection pump fuse and inspect fuse condition.
- There is a restriction in the air injection tube. Excessive carbon build-up may have blocked air flow.
- Faulty air injection diverter valve. It is not uncommon for diverter valves to fail. The diverter valve is constantly exposed to high heat.
- Faulty air diverter valve solenoid. This fault should also trigger a P0491, except if your vehicle is equipped with a vacuum controlled diverter valve.
- Plugged catalytic converter increasing back pressure in the exhaust and not allowing for adequate air flow downstream of the exhaust manifold. This fault causing a P0410 is rare. If the CAT is defective it will trigger one or more additional catalytic converter related trouble codes.
- Oxygen sensor(s) failing but not yet completely defective. Slow oxygen sensor switch rate.
What symptoms will my vehicle experience when trouble code P0410 is set?
- Your vehicle check engine light (CEL), Malfunction Indicator Lamp (MIL) or Service Engine Soon light will be illuminated and freeze frame data stored with information regarding engine sensor data at the time when the ECC detected the air injection fault. Trouble code P0410 will also be recorded in the ECC ROM memory.
- No driveability problems should be experienced.
- Fuel economy may be diminished.
How can I fix a P0410 problem and where should I start?
Begin by ensuring the air pump motor works. Start your vehicle's engine while it's cold and listen to the air pump. It should run for at least one minute. If you do not hear the motor running, the fault may be with the motor, the air injection motor fuse, the air injection pump relay, or the power connector to the motor.
Wait for your vehicle to cool down fully (cold-start), disconnect the air pump motor electrical connection, start the engine and check for voltage. If voltage exists, then you may suspect a defective air pump motor. Replace the motor and continue testing. If the air pump does run, disconnect the tube going to the diverter valve and check for air flow. If no air flow, inspect the tube for obstruction. This section of the air tube will usually be clear of obstruction and you should move on to checking the diverter valve and solenoid, as well as the section of the air supply tube after the diverter valve and check valve. Side note, carbon will be collected nearest the exhaust system.
The solenoid will be located next to the diverter valve. It will have two vacuum lines. One leading from the intake manifold to the solenoid (vacuum supply), and one vacuum line leading to the diverter valve. While the engine is idling check for supply vacuum. Disconnect the vacuum hose first from the manifold side and check for vacuum, and next from the solenoid side. You should see approx. 18in of vacuum during idle. If no vacuum is present, inspect the vacuum line for cracks and/or disconnection. Note, if the diverter valve is electrically operated, there will be no vacuum lines to inspect. Instead, using a voltmeter, you'll need to check for voltage (5v-12v) at the solenoid terminals.
If vacuum or electrical solenoid problems do not exist, move on to the diverter valve itself. The diverter valve will be located closest to the exhaust manifold. It is usually an aluminum or steel valve with a metal hose leading to the exhaust manifold (in some cases to the catalytic converter as well) and a rubber or plastic hose leading to the air pump. Disconnect the shorter metal tube leading to the exhaust manifold. More than likely you will find a large amount of carbon build up here. Clean the tube out. Inspect the exhaust manifold as well. If it appears to be plugged up, you may need to remove the manifold and clean out the carbon.
Somewhere along the line of performing the steps above you should find the fault causing your vehicle to trigger a P0410 trouble code.
After the repair(s), you'll need to reset your vehicle's ECC in order to turn off the check engine light. You may also choose to not reset the computer and drive your vehicle at least 300 hundred miles over the course of a few days to see if the CEL will turn off on its own. Technically, if your repair was successful, the ECC will clear the P0410 after three successful trips (three engine cold-starts) and turn off the light.
If you choose to reset the computer manually (using a scan tool), you'll need to complete a drive cycle in order to complete (make READY) the required emission readiness monitors and be ready to pass the smog check. Driving your vehicle for a week, in both highway and city roads, will complete the drive cycle. A smog station will more than likely clear the trouble code manually since they will not have the convenience of driving the vehicle over an extend amount of time. At the repair shop, the P0410 will be cleared and the vehicle driven on a short trip after a cold-start in order to verify the repair. You will than be required to complete the drive cycle before returning to the smog station for final inspection. Note, manually clearing the ECC of trouble codes erases emission monitor data. Waiting for the light to turn off on its own does not.
- Check the air pump for operation.
- Check the air pump fuse (electric pump only).
- Check air injection pump relay (electric pump only).
- Check air injection tube for restriction.
- Check diverter valve for proper opening and closing.
- Check diverter valve solenoid for proper operation and vacuum supply (if vacuum operated)
- Check air injection check valve. Observe whether stuck in closed or open position.
- Check exhaust manifold and all air injection passages for excessive carbon deposit.
- Test oxygen sensor(s) for switch speed. Ensure oxygen sensor(s) produce voltage accurately and with quick reaction time to voltage increase and decrease.
Can I drive my vehicle with a P0410 trouble code and illuminated CEL?
- You may drive your vehicle with a P0410 however keep in mind your vehicle will not pass a smog inspection.
- Problems with the air injection system will not cause any driveability symptoms.
- The check engine light or malfunction indicator lamp will be illuminated as long as a P0410 is recorded in the ECC.
