P0411
DTC P0411
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC P0411
- Secondary Air Injection System Incorrect Air Flow Detected
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The secondary air injection system aids in the reduction of hydrocarbon emissions during a cold start. The electric air pump forces fresh air into the exhaust stream in order to accelerate the catalyst operation. A pressure sensor is used to monitor the air pressure from the secondary air injection pump. The Engine Control Module (ECM) supplies voltage to the 5 V reference circuit and provides a ground for the low reference circuit. The sensor provides a signal voltage to the ECM relative to the pressure changes within the secondary air system.
Ignition voltage is supplied directly to both the secondary air injection pump relay and the secondary air injection valve relay coils. The ECM activates the secondary air system by simultaneously supplying a ground reference to the secondary air injection pump and valve relay coils. This energizes the relays and allows battery (B+) voltage to be connected to the pump and the control valve/pressure sensor assembly through the relay contacts. The pump motor energizes and the control valve opens allowing air flow into the exhaust manifold.
Conditions for Running the DTC
* DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0351, P0352, P0353, P0354, P0412, P0418, P0420, P0606, P0641, P0651, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P2430, P2431, P2432 or P2433 are not set.
* The ignition voltage is between 10-32 V.
* The intake air temperature (IAT) is greater than -11°C (+12°F).
* The barometric pressure (BARO) is greater than 60 kPa (8.7 psi).
* The engine coolant temperature (ECT) is between -11 to +60°C (12-140°F).
* The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi.
* The engine speed is less than 5,000 RPM.
* The mass air flow (MAF) is less than 50 g/s.
* Greater than 60 min has elapsed since the last cold start.
* The Secondary Air Injection system is commanded ON.
* DTC P0411 runs once per trip at start up when the above conditions are met.
Conditions for Setting the DTC
* The difference between the predicted system pressure and the actual system pressure is greater than or less than the calibrated thresholds.
* DTC P0411 sets within 10 s when the above condition is met.
Action Taken When the DTC Sets
DTC P0411 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0411 is a Type B DTC.
Diagnostic Aids
A slow responding or skewed Secondary Air Pressure sensor may cause this DTC to set.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Secondary Air Injection System Description (Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Note: Verify the battery is fully charged before proceeding with this diagnostic procedure. The Air Pump output will vary with system voltage.
1. Ignition ON, observe the DTC information with a scan tool. 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 (Diagnostic Trouble Code (DTC) List - Vehicle).
2. Compare the scan tool BARO pressure parameter to the Altitude Versus Barometric Pressure (Altitude Versus Barometric Pressure) table. The BARO pressure should be within the specified range displayed in the table for the specific altitude.
• If not within the specified range, refer to DTC P0106 (P0106) for further diagnosis.
3. Compare the scan tool Air Pressure Sensor pressure parameter to the BARO pressure parameter. The parameters should be within 3 kPa (0.4 psi).
• If greater than the specified range, refer to DTC P2430-P2433 (P2430).
4. Command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. Listen or feel for Solenoid Valve operation. The Solenoid Valve should respond to the scan tool commands. Repeat as necessary in order to verify Air Solenoid Valve operation.
5. Engine idling, command the Secondary Air Injection Pump Relay ON with a scan tool while observing the Secondary Air Injection Pressure Sensor parameter. The reading should change greater than 15 kPa (2.2 psi).
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.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the Q29 Secondary Air Injection Solenoid Valve.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the ground circuit terminal 4 and ground.
• If greater than the specified range, repair the ground circuit for an open/high resistance.
3. Connect a test lamp between the Q29 Secondary Air Injection Solenoid Valve ignition voltage circuit terminal 5 and ground.
4. Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool. The test lamp should respond to the scan tool commands.
• If the test lamp is always OFF, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay.
• If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the Secondary Air Injection Solenoid Valve relay.
5. Ignition OFF, remove the Q29 Secondary Air Injection Solenoid Valve.
6. Connect the Q29 Secondary Air Injection Solenoid Valve harness connector.
7. Ignition ON, command the Secondary Air Injection Solenoid Valve Open and Closed with a scan tool while observing the check valve assembly. The valve should open and close in response to the scan tool commands.
• If the valve does not operate as specified, replace the Q29 Secondary Air Injection Solenoid Valve.
8. Inspect the Secondary Air Injection Solenoid Valve and air flow passages for the following conditions:
* Blocked or contaminated Secondary Air Injection pressure sensor port.
* Damaged Secondary Air Injection Solenoid valve.
* Blocked or restricted Secondary Air Injection Solenoid valve manifold, cylinder head and exhaust manifold air flow passages.
* Leaks in Secondary Air Injection Solenoid valve manifold, cylinder head and exhaust manifold.
• If a condition is located, repair or replace the affected component as necessary.
9. Ignition OFF, disconnect the harness connector at the G21 Secondary Air Injection Pump.
10. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the ground circuit terminal B and ground.
• If greater than the specified range, repair the ground circuit for an open/high resistance.
11. Connect a test lamp between the G21 Secondary Air Injection Pump ignition voltage circuit terminal A and ground.
12. Ignition ON, command the Secondary Air Injection Pump Relay ON and OFF with a scan tool. The test lamp should respond to the scan tool commands.
• If the test lamp is always OFF, test the ignition circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the Secondary Air Injection Pump relay.
• If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the Secondary Air Injection Pump relay.
13. Ignition OFF, install the harness connector at the G21 Secondary Air Injection Pump.
14. Disconnect the Secondary Air Injection Pump Hose from the Q29 Secondary Air Injection Solenoid Valve.
15. Ignition ON, command the Secondary Air Injection Pump ON with a scan tool. Verify airflow to the Secondary Air Injection Solenoid Valve.
• If there is limited or no airflow to the Secondary Air Injection Solenoid Valve, inspect for the following:
* All Secondary Air Injection System Hoses/pipes for a restriction or blockage
* Secondary Air Injection Pump Hose/Pipe for leaks or loose connections
• If a condition is located, repair or replace the affected component as necessary.
16. If all circuits hoses/pipes and air flow passages test normal, replace the G21 Secondary Air Injection Pump.
Component Testing
1. Ignition OFF, disconnect the appropriate relay.
2. Test for the following resistance between terminals 85 and 86:
* 50-75 ohm - Secondary Air Injection Pump Relay
* 70-110 ohm - Secondary Air Injection Solenoid Valve Relay
• If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 86 and 87
* 86 and 30
* 85 and 87
* 87 and 30
• If not the specified value, replace the Secondary Air Injection Pump Relay.
4. Install a 15 A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground. Test for less than 2 ohm between terminals 87 and 30.
• If not the specified value, replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Secondary Air Injection Pipe Replacement (Secondary Air Injection Pipe Replacement)
* Secondary Air Injection Pump Hose Replacement (Secondary Air Injection Pump Hose Replacement)
* Secondary Air Injection Check Valve Replacement (Secondary Air Injection Check Valve Replacement)
* Secondary Air Injection Pump Replacement (Service and Repair)