For 1990-2009 cars
Engine Controls Components
Air Injection Pump, Air Injection Pump Relay K12, MAF and ECT Sensors
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The purpose of the secondary air injection (AIR) system is to reduce hydrocarbon (HC), the carbon monoxide (CO), and the oxides of nitrogen (NOx) exhaust emissions by causing any combustible gases in the exhaust to reburn. This also causes the catalytic converters and the heated oxygen (HO2S) sensors to reach the normal operating temperatures more quickly, which will allow Closed Loop operation to occur earlier.

When the engine is started, the engine control module (ECM) commands the AIR pump relay and the AIR cutoff valve vacuum control solenoid ON, injecting clean air into the engine exhaust ports. The ECM switches the AIR system OFF when the oxygen sensors become active. The AIR cutoff valve prevents air from being drawn into the system when the AIR pump is OFF. The vacuum to the valve is controlled by the AIR cutoff valve vacuum control solenoid. A check valve close to the engine prevents hot exhaust gases from backing up into the AIR system.

### Conditions for Running the DTC

• | The following DTCs are not set: P0110, P0115, P0116, P0130, P0131, P0132, P0134, P0150, P0151, P0152, P0154, P0171, P0172, P0174, P0175, P0300-P0306, P0412, P0418, P0440, P0442, P0443, P0446 or P0455.

• | The intake air temperature (IAT) is between 5°C (41°F) and 40°C (104°F).

• | The engine coolant temperature (ECT) is between 18.8°C (65.8°F) and 105°C (221°F).

• | The engine is at idle.

• | The vehicle speed is 0 km/h (0 mph)

• | The AIR system is active.

### Conditions for Setting the DTC

The ECM has determined that reduced or no secondary air flow is present.

### Action Taken When the DTC Sets

The ECM illuminates the malfunction indicator lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.

### Conditions for Clearing the MIL/DTC

• | The ECM turns OFF the MIL after three consecutive drive trips that the diagnostic runs and passes.

• | A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.

• | The scan tool clears the MIL/DTC.

### Diagnostic Aids

• | Use the J 35616 connector test adapter kit for any test that requires probing the ECM harness connector or a component harness connector.

• | Using the Freeze Frame data may aid in locating an intermittent condition. If the DTC cannot be duplicated, review the information in the Freeze Frame. Try to operate the vehicle within the same Freeze Frame conditions, the RPM, the MAF, the vehicle speed, the temperature, etc., that were noted. This process may help in order to recreate the condition.

• | A Service Bay Test is available on the scan tool for the AIR System. This test will command the ECM to run the on-board diagnostic test for the AIR system. If a fault is present, the appropriate DTC will set.

• | Inspect the AIR pump check valve for a restriction or damage. Inspect the hoses before and after the check valve for evidence of heat damage. A heat damaged hose indicates that the check valve is stuck open allowing exhaust gas back into the AIR system. A stuck open check valve may allow exhaust gas to damage the cutoff valve.

• | Check the air pump for reduced flow. A pump that operates, but does not produce enough flow, will cause this DTC to set.

• | When testing the system for a short to ground, test the circuit on the switched side of the relay. A short can be located on the switched side of the relay and includes an air pump that draws excessive current. The air pump may have an in-rush current draw of up to 90 amps when first operating the pump. This is considered normal. The current should stabilize to about 20 amps once the pump is running. Use caution if trying to operate the pump with a fused jumper. The in-rush current required to operate the pump may open the fuse if the fuse is not designed to handle the in-rush current.

• | For an intermittent, refer to Intermittent Conditions .

#### DTC P0411 - Secondary Air Injection (AIR) System No Flow Detected

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Is DTC P0412 or P0418 also set? | -- | Go to DTC P0412 Secondary Air Injection (AIR) Solenoid Control Circuit or DTC P0418 Secondary Air Injection (AIR) Pump Relay Control Circuit | Go to Step 3
3 |

1. Turn ON the ignition, with the engine OFF.
2. Using a scan tool, command the AIR pump relay ON and OFF.

Does the AIR pump turn ON and OFF?

--

Go to Step 7

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Disconnect the electrical connector from the AIR pump.
3. Using a test lamp connected to ground, probe the AIR pump feed circuit in the harness connector.
4. Turn ON the ignition, with the engine OFF.
5. Using a scan tool, command the AIR pump relay ON.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 6

5 | With a test lamp connected to B+, probe the AIR pump ground circuit in the harness connector. Does the test lamp illuminate? | -- | Go to Step 23 | Go to Step 16
6 |

1. Turn OFF the ignition.
2. Disconnect the AIR pump relay.
3. Using the test lamp connected to ground, probe the battery positive voltage supply circuit to the relay.

Does the test lamp illuminate?

--

Go to Step 15

Go to Step 13

7 |

1. Disconnect the vacuum hose from the cutoff valve.
2. Start the engine and allow it to idle.
3. Using a scan tool, command the AIR solenoid valve ON.
4. Measure the vacuum at the cutoff valve

Is the vacuum above the specified value?

33 kPa (10 in Hg)

Go to Step 10

Go to Step 8

8 |

1. Turn OFF the ignition.
2. Disconnect the manifold vacuum supply hose at the AIR solenoid valve.
3. Start the engine and allow it to idle.
4. Measure the vacuum at the solenoid valve

Is the vacuum above the specified value?

33 kPa (10 in Hg)

Go to Step 9

Go to Step 20

9 |

1. Turn OFF the ignition.
2. Inspect the vacuum hose from the solenoid to the cutoff valve for a leak or restriction.
3. Repair or replace the hose as necessary.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 25

10 |

1. Turn OFF the ignition.
2. Use a hand held vacuum pump in order to apply the specified vacuum to the cutoff valve.

Does the valve hold vacuum?

33 kPa (10 in Hg)

Go to Step 11

Go to Step 26

11 |

1. With the vacuum still applied to the cutoff valve, disconnect the AIR hose at the check valve.
2. Turn ON the ignition with the engine OFF.
3. With a scan tool, command the AIR pump relay ON.

Is the airflow present at the hose when the pump is running?

--

Go to Step 19

Go to Step 12

12 |

1. Disconnect the AIR hose from the air pump at the cutoff valve.
2. With a scan tool, command the AIR pump relay ON.

Is airflow present at the hose when the pump is running?

--

Go to Step 17

Go to Step 18

13 |

1. Inspect the B+ supply for an open fuse. If the fuse was open, locate and repair the cause of the short. Refer to Diagnostic Aids.
2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.
3. Replace the fuse.

Did you find and repair the condition?

--

Go to Step 28

Go to Step 14

14 | Repair the open B+ circuit to the relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 28 | --
15 |

1. Test for an open or high resistance in the AIR pump feed circuit between AIR pump relay and AIR pump.
2. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 28

Go to Step 22

16 | Repair the open/high resistance in the AIR pump ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 28 | --
17 | Inspect the air hose between the cutoff valve and the check valve for a restriction or leak. Repair or replace as necessary. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 26
18 | Inspect the air hose between the air pump and the cutoff valve for a restriction or leak. Repair or replace as necessary. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 21
19 |

1. Inspect the AIR system for the following conditions:

• | Plugged or restricted AIR check valve

• | Blocked or restricted pipes/hoses between the check valve and the manifolds.

• | Blocked or restricted ports in the exhaust manifolds

• | AIR cut off valve is stuck open

2. Repair as necessary. Refer to Secondary Air Injection Check Valve and Check Valve Pipe Replacement .

Did you find and correct the condition?

--

Go to Step 28

Go to Diagnostic Aids

20 | Repair the leaking or restricted vacuum supply hose. Did you complete the repair? | -- | Go to Step 28 | --
21 | Inspect the AIR pump inlet filter for a restriction. Replace as necessary. Did the filter require replacement? | -- | Go to Step 28 | Go to Step 27
22 | Test for a poor connection or terminal tension at the relay connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If a repair is necessary refer to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 24
23 | Test for a poor connection or poor terminal tension at the AIR pump harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. If a repair is necessary refer to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 28 | Go to Step 27
24 | Replace the air pump relay. Did you complete the replacement? | -- | Go to Step 28 | --
25 | Replace the AIR vacuum solenoid. Refer to Secondary Air Cutoff Valve Vacuum Solenoid Replacement . Did you complete the replacement? | -- | Go to Step 28 | --
26 | Replace the AIR cutoff valve. Refer to Secondary Air Injection Cut Off Valve Replacement . Did you complete the replacement? | -- | Go to Step 28 | --
27 | Replace the AIR pump. Refer to Secondary Air Injection Pump Replacement . Did you complete the replacement? | -- | Go to Step 28 | --
28 |

1. Using the scan tool, clear the DTCs.
2. Start the engine.
3. Allow the engine to idle until the engine reaches the normal operating temperature.
4. Select DTC and the Specific DTC function.
5. Enter the DTC number that was set.
6. Operate the vehicle within the Conditions for Running this DTC until the scan tool indicates that the diagnostic Ran.

Does the scan tool indicate that the diagnostic Passed?

--

Go to Step 29

Go to Step 2

29 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK