P0410

CIRCUIT DESCRIPTION
The secondary air injection (AIR) system is designed to reduce exhaust emissions during engine starts. The powertrain control module (PCM) activates the AIR system by supplying a ground to the AIR pump relay. This action energizes the AIR pump and the vacuum control solenoid, applying vacuum to the AIR shut-off valve, opening the valve. The AIR pump then forces air past the shut-off valve, through the pipes/hoses and the exhaust check valve into the exhaust system to accelerate catalyst operation. When inactive, the shut-off valve prevents airflow in both directions. The PCM will perform a passive test while the AIR system is performing normally. During the test the PCM monitors the O2S voltages, expecting a drop below 100 mV, approaching near 0 mV. The PCM expects the short term fuel trim (FT) to increase at the same time. If the test fails or is inconclusive, the PCM will run up to 3 diagnostic active tests using the O2S voltage parameter and short term FT parameter to verify the system operation. When the PCM detects an insufficient O2S response, DTC P0410 sets.

CONDITIONS FOR RUNNING THE DTC
- DTCs P0105, P0107, P0108, P0112, P0113, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0171, P0172, P0300, P0301-P0304, P0341, P0506, P0507, P0601, P0602, are not set.
- The AIR system is commanded ON for more than 20 seconds.
- The intake air temperature (IAT) is between 1-151°C (32-302°F).
- The engine coolant temperature (ECT) is between 5-114°C (41-230°F).
- The battery voltage is more than 11.0 volts.
- The engine run time is more than 200 seconds.
- The vehicle is operating in fuel trim cell of 16 or 17.
- The throttle position (TP) sensor changes less than 5 percent.
- The manifold absolute pressure (MAP) sensor is less than 30 kPa.
- The injector base pulse width is more 0.650 ms.
- The engine speed is more than 1,150 RPM for automatic transmissions.
- The engine speed is more than 1,000 RPM for manual transmissions.

CONDITIONS FOR SETTING THE DTC
The control module does not detect that the O2S is less than 50 mV for 1 second during a 3 second active test for 3 consecutive active tests.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
- An AIR solenoid stuck open or leaking vacuum may hold the shut-off valve open. An audible exhaust noise may be heard through the AIR pump inlet hose. This condition may not set a code and may cause fuel trims to indicate high percent at an idle.
- Verify proper connections of the vacuum hoses. Reversed connections at the AIR solenoid may cause the AIR shut-off valve to stick open.
- Low system airflow may cause this DTC to set.
- Excessive exhaust system back-pressure may cause this DTC to set.
- An intermittent may be caused by any of the following conditions:
- Pinched, restricted, split, or damaged pipes/hoses or vacuum lines
- Restrictions in the AIR pump inlet hose
- Damaged contacts in the AIR pump relay-Tap on the AIR pump relay to attempt to duplicate an intermittent condition.
- Heat damage to the AIR crossover hose may indicate an exhaust check valve failure.
- Water or debris ingested into the AIR pump may cause this DTC to set.
- Observe the Freeze Frame/Failure Records to see what conditions set P0410.

Thoroughly inspect any circuits that are suspected of causing the intermittent condition. Refer to Diagnostic Aids for Circuit Testing and Wiring Repair Procedures.

If a repair is necessary, refer to Diagnostic Aids for circuit Testing and Wiring Repair Procedures.

TEST DESCRIPTION

Steps 1-2:

Steps 3-7:

Steps 8-11:

Steps 12-13:

Steps 14-16:

Steps 17-19:

Steps 20-22:

Steps 23-25:

Steps 26-30:

Steps 31-35:

Steps 36-41:

Steps 42-46:

Steps 47-51:

Steps 52-59:

Steps 60-63:

The numbers below refer to the step numbers on the diagnostic table.
12. This step determines if excessive resistance is the cause for an inoperative AIR pump. Two ohms of resistance on this circuit can prevent the AIR pump from running.
14. This step determines if excessive resistance is the cause for an inoperative AIR pump. Two ohms of resistance on this circuit can prevent the AIR pump from running.
15. This step determines if the AIR system is operating normally.
17. This step inspects for a restriction in the engine vacuum supply to the AIR shut-off valve.
21. This step determines if the lack of air is caused by an open or a restriction in the AIR supply hose, or if an inoperative AIR shut-off valve is causing this condition. There should be a steady forceful flow of air from the AIR pump.