The secondary air injection (AIR) system aids in the reduction of hydrocarbon emissions during a cold start. The system forces fresh filtered air into the exhaust stream in order to accelerate the catalyst operation. An electric air pump, the secondary AIR injection pump, provides filtered air on demand to the AIR control solenoid valve/pressure sensor assembly. The AIR control solenoid valve/pressure sensor assembly controls the flow of air from the AIR pump to the exhaust manifold. The AIR valve relay supplies the current needed to operate the AIR control solenoid valve/pressure sensor assembly. A pressure sensor is used to monitor the air flow from the AIR pump. The control module supplies the internal pressure sensor with a 5-volt reference, an electrical ground, and a signal circuit.

The AIR diagnostic uses 3 phases to test the AIR system:

1. DTCs P0411 and P2430 run during Phase 1
2. DTCs P2430 and P2440 run during Phase 2
3. DTC P2444 runs during Phase 3

During phase 1, both the AIR pump and the solenoid valve are activated. Normal secondary air function occurs. Expected system pressure is 8-10 kPa above BARO.

During phase 2, only the AIR pump is activated. The solenoid valve is closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 20-25 kPa above BARO.

During phase 3, neither the AIR pump nor the solenoid valve is activated. AIR pump deactivation is tested. Expected system pressure equals BARO.

In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The control module can detect faults in the AIR pump, AIR control solenoid valve/pressure sensor assembly, and the exhaust check valve. The pressure sensor can also detect leaks and restrictions in the secondary AIR system plumbing.

DTC P0411 is a Type B DTC.

DTC P0411 is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 36169-HD Heavy Duty Fused Jumper

1. Verify that DTCs P0412, P0418, P2430, P2431, P2432, P2433, P2440, or P2444 are not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

2. Ignition ON, command the AIR pump relay ON and OFF with a scan tool. The air pump should turn ON and OFF

⇒	If the air pump does not turn ON or OFF, refer to Secondary Air injection Pump Malfunction.

3. Command the AIR solenoid relay ON and OFF with a scan tool. The AIR solenoid valve should click with each command.

⇒	If the AIR solenoid valve does operate as specified, refer to Secondary Air Injection Solenoid Valve Malfunction.

4. Engine running, command the AIR pump relay ON with a scan tool while observing the AIR Pressure Sensor parameter. The reading should be 20-25 kPa above the BARO reading.

⇒	If less than the specified range, refer to Secondary Air Injection System Pressure Low.

⇒	If greater than the specified range, refer to Secondary Air Injection System Pressure High.

5. Engine running, command the AIR system ON while observing the AIR Pressure Sensor parameter. The reading should be 8-10 kPa above BARO.

⇒	If less than the specified range, refer to Secondary Air Injection System Pressure Low.

⇒	If greater than the specified range, refer to Secondary Air Injection System Pressure High.

6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Secondary Air Injection Pump Malfunction

1. Ignition OFF, disconnect the AIR pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal and ground.

⇒	If the test lamp illuminates, test the controlled output circuit for a short to voltage.

3. Verify that a test lamp illuminates between the AIR pump relay coil ignition circuit terminal and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, replace the AIR pump relay.

4. Verify that a test lamp illuminates between the AIR pump relay switch B+ circuit terminal and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the controlled output circuit for a short to ground.

5. Ignition OFF, disconnect the harness connector at the AIR pump.
6. Test for less than 2 ohms between the AIR pump ground circuit terminal B and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the AIR pump.
8. Connect the J 36169-HD with a 40A fuse between the AIR pump relay switch B+ circuit terminal and the controlled output circuit terminal. Verify the AIR pump is activated.

⇒	If the AIR pump does not activate, test the controlled output circuit for an open/high resistance. If the circuit tests normal, test or replace the AIR pump.

9. Remove the J 36169-HD .
10. Connect a test lamp between the AIR pump relay coil ignition circuit terminal and the AIR pump relay control circuit terminal.
11. Ignition ON, command the AIR pump relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the AIR pump relay control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the AIR pump relay control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

12. If all circuits test normal, replace the air pump relay.

Secondary Air Injection Solenoid Malfunction

1. Ignition OFF, disconnect the AIR solenoid relay.
2. Ignition ON, verify that a test lamp does not illuminate between the controlled output circuit terminal and ground.

⇒	If the test lamp illuminates, test the controlled output circuit for a short to voltage.

3. Verify that a test lamp illuminates between the AIR solenoid relay coil ignition circuit terminal and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the AIR solenoid relay switch B+ circuit terminal and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the controlled output circuit for a short to ground.

5. Ignition OFF, disconnect the harness connector at the AIR solenoid valve.
6. Test for less than 2 ohms between the AIR solenoid ground circuit terminal 4 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. Connect the harness connector at the AIR solenoid valve.
8. Connect a 10A fused jumper wire between the AIR solenoid relay switch B+ circuit terminal and the controlled output circuit terminal. Verify the AIR solenoid valve activates.

⇒	If the AIR solenoid valve does not activate, test the controlled output circuit for an open/high resistance. If the circuit tests normal, test or replace the AIR solenoid valve.

9. Remove the 10A fused jumper wire.
10. Connect a test lamp between the AIR solenoid relay coil ignition circuit terminal and the relay coil control circuit terminal.
11. Ignition ON, command the AIR solenoid relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.

12. If all circuits test normal, replace the AIR solenoid relay.

Secondary Air Injection System Pressure Low

1. Engine running, inspect for exhaust leaks between the AIR solenoid valve and the catalytic converter.

⇒	If an exhaust leak is detected, repair as necessary.

2. Ignition OFF, disconnect the AIR pump relay.
3. Engine running, connect the J 36169-HD with a 40A fuse between the AIR pump relay switch B+ circuit terminal and the controlled output circuit terminal. Verify the AIR Pressure Sensor parameter is not 20-25 kPa above BARO.

⇒	If 20-25 kPa above BARO, replace the AIR pump relay.

4. Ignition OFF, remove the fused jumper wire and connect the AIR pump relay.
5. Remove the air inlet hose at the AIR pump.
6. Engine running, command the AIR system ON while observing the AIR Pressure Sensor parameter. Verify the reading is not 8-10 kPa above BARO.

⇒	If 8-10 kPa above BARO, the AIR pump inlet hoses/pipes are restricted. Remove the restriction or replace the inlet hose/pipe.

7. Ignition OFF, disconnect the hose at the AIR pump outlet.
8. Disconnect the hose at the AIR solenoid valve inlet.
9. Install a length of standard 1 inch I.D. (25.4 mm) hose from the AIR pump outlet to the AIR solenoid valve inlet.
10. Engine running, command the AIR system ON while observing the AIR Pressure Sensor parameter. Verify the reading is not 8-10 kPa above BARO.

⇒	If 8-10 kPa above BARO, test/inspect the AIR pump outlet hoses/pipes for leaks or restrictions.

11. Test all AIR pump wiring and connections for less than 2 ohms. If the wiring and connections test normal, replace the AIR pump.

Secondary Air Injection System Pressure High

1. Ignition OFF, remove the AIR solenoid valve.
2. Connect the AIR pump outlet pipe/hose to the AIR solenoid valve.
3. Connect the AIR solenoid harness at the AIR solenoid valve.
4. Engine running, command the AIR system ON while observing the AIR Pressure Sensor parameter. The reading should be less than 11 kPa above BARO.

⇒	If greater than the specified value, replace the AIR solenoid valve.

5. Inspect the AIR solenoid valve gaskets for proper alignment. If normal, test/inspect the cylinder head or exhaust manifold for a restriction.

Relay Test

1. Test between the normally-closed switch terminals, if any, for 0 ohms.
2. Test between the normally-open switch terminals for infinite ohms.
3. Test between each switch terminal and either coil terminal for infinite ohms.
4. Connect the relay coil terminals to ground and fused power to energize the relay.
5. Test between each switch terminal and each coil terminal for 0 volts.
6. Test between the normally-closed switch terminals, if any, for infinite ohms.
7. Test between the normally-open switch terminals for 0 ohms.

Pump

Connect the AIR pump to fused battery voltage and ground and observe pressurized airflow at the pump outlet.

Solenoid Valve

Apply fused battery voltage and ground to the solenoid and verify that the valve opens and closes completely as voltage is applied to and removed from the solenoid. Observe that the valve is not obstructed or leaking.

1. With the ignition ON and the engine OFF, observe that the AIR pump is not operating.
2. With the engine RUNNING, enable the AIR system with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 8-10 kPa above BARO.
3. With the engine RUNNING, enable the AIR pump with a scan tool and observe that the AIR Pressure Sensor parameter equals approximately 20-25 kPa above BARO.