P2440
DTC P2440
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 P2440
- Secondary Air Injection System Cut-Off Valve Stuck Open
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 in each bank is used to monitor the air flow from the secondary air injection pump. The engine control module (ECM) supplies voltage to the 5-volt reference circuits and supplies a ground to the low reference circuits. The sensors provide a signal voltage to the ECM relative to the pressure changes within the secondary air injection system.
Ignition voltage is supplied to the secondary air injection pump relay and the secondary air injection solenoid valve (shutoff and check valve) relay. The ECM activates the relays by grounding the control circuits. When the relay contacts close, voltage is supplied to the pump and the valves, which turns the pump on and opens the valves.
The diagnostic uses 3 phases to test the secondary air injection system:
* DTCs P0411, P2430 and P2435 run during Phase 1
* DTCs P2430, P2435 and P2440 run during Phase 2
* DTC P2444 runs during Phase 3
During phase 1, both the secondary air injection pump and the secondary air injection solenoid valves are activated. Normal secondary air function occurs. Expected system pressure is 5-13 kPa (0.7-1.9 psi) above BARO.
During phase 2, only the secondary air injection pump is activated. The solenoid valves are closed. Pressure sensor performance and solenoid valve deactivation are tested. Expected system pressure is 14-22 kPa (2.0-3.2 psi) above BARO.
During phase 3, neither the secondary air injection pump nor the secondary air injection solenoid valves are activated. Secondary air injection pump deactivation is tested. Expected system pressure equals BARO.
Conditions for Running the DTC
* DTC P0101, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0201-P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P0300, P0351, P0352, P0353, P0354, P0355, P0356, P0412, P0418, P0420, P0430, P0606, P0641, P0651, P124A, P124B, P124C, P124D, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P216B, P216C, P216E, P216F, P2227, P2228, P2229, P2230, P2430, P2431, P2432, P2433, P2435, P2436, P2437, or P2438 is not set.
* Greater than 60 min has elapsed since the last cold start.
* The ignition voltage is between 10-32 V.
* The engine speed is less than 5,000 RPM.
* The intake air temperature (IAT) is greater than -10°C (+14°F).
* The engine coolant temperature (ECT) is between -10 and +56°C (14-133°F).
* The barometric pressure (BARO) is greater than 74 kPa (10.7 psi).
* The manifold absolute pressure (MAP) sensor is greater than 20 kPa (2.9 psi).
* The mass air flow (MAF) is less than 50 g/s.
* The secondary air injection pump is commanded ON.
* Secondary air injection diagnostic test Phase 1 has run and passed.
* DTC P2440 runs once per ignition cycle when the above conditions are met.
Conditions for Setting the DTC
The ECM detects that average difference between the predicted system pressure and the actual system pressure is less than a calibrated threshold for greater than 8 s.
Action Taken When the DTC Sets
DTC P2440 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P2440 is a Type B DTC.
Diagnostic Aids
Ice buildup due to condensation/water in the air passages or pump 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 Fuel Pump and Level Sensor Assembly
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, verify that DTC P0412, P0418, P2430, P2431, P2432, P2433, P2435, P2436, P2437, or P2438 is not set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Ignition ON, verify the scan tool BARO pressure parameter is within the range specified in the Altitude Versus Barometric Pressure Altitude Versus Barometric Pressure table.
• If not within the specified range, refer to DTC P2227-P2230 P2227.
3. Verify the scan tool Secondary Air Injection Pressure Sensor Bank 1, Secondary Air Injection Pressure Sensor Bank 2 and the BARO pressure parameters are within 3 kPa (0.4 psi).
• If not within the specified range, replace the appropriate Q29 secondary air injection solenoid valve or valves.
4. Command the Secondary Air Injection Solenoid Open and Closed with a scan tool. You should hear and feel the KR26 secondary air injection solenoid valve relay click.
Note: Engine coolant temperature must be greater than 5°C (41°F) to enable scan tool device control. It may be necessary to use one of the methods listed below to verify valve operation:
* Use a stethoscope to listen for check valve operation.
* Disconnect the secondary air injection pipe from the secondary air injection solenoid valve and visually inspect the valve inlet port for valve stem movement.
* Disconnect the secondary air injection valve and verify airflow through the valve when commanding the Secondary Air Injection System to Active with a scan tool.
5. Verify the Q29 secondary air injection check valves open and close when commanding the Secondary Air Injection Solenoid Open and Closed with a scan tool.
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 appropriate Q29 secondary air injection solenoid valve
2. Connect a test lamp between the Q29 secondary air injection solenoid valve ignition voltage circuit terminal 5 and ground.
3. Ignition ON, command the Secondary Air Injection Solenoid Open and Closed with a scan tool. The test lamp should turn ON and OFF.
• If the test lamp is always ON, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the KR26 secondary air injection solenoid valve relay.
4. Verify the following conditions do not exist:
* Hoses/pipes restricted or blocked upstream of valve
* Hoses/pipes leaking or disconnected
* Damaged or restricted secondary air injection pump
* Damaged secondary air injection check valve
• If a condition is located, repair as necessary.
5. If all components test normal, test or replace the Q29 secondary air injection solenoid valve.
Component Testing
1. Disconnect the appropriate Q29 secondary air injection solenoid valve from the engine.
2. Connect the harness connector at the Q29 secondary air injection solenoid valve.
3. Connect the secondary air injection pipe between the Q29 secondary air injection solenoid valve and the G21 secondary air injection pump.
4. Command the Secondary Air Injection Pump Relay ON with a scan tool. Verify there is NO airflow through the Q29 secondary air injection solenoid valve.
• If there is airflow through the valve, replace the Q29 secondary air injection solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Secondary Air Injection Bypass Valve Replacement - Left Side Secondary Air Injection Bypass Valve Replacement - Left Side for secondary air injection solenoid valve replacement-Left Side
* Secondary Air Injection Bypass Valve Replacement - Right Side Secondary Air Injection Bypass Valve Replacement - Right Side for secondary air injection solenoid valve replacement-Right Side