Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptor
DTC P2440 : Secondary Air Injection (AIR) System Shut-Off Valve Stuck OpenDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Pressure Sensor 5-Volt Reference Voltage | P0335, P0651, P2135, P2432 | P2432 | P2431, P0651 | P2430, P2431 |
Pressure Sensor Signal | P2432 | P2432 | P2433 | P2430, P2431 |
Pressure Sensor Low Reference | -- | P2433 | -- | P0411, P2431 |
Pump Supply | P0411 | P0411 | 2444 | -- |
Pump Ground | -- | P0411 | -- | -- |
Solenoid Supply | P0411 | P0411 | P2440 | -- |
Solenoid Ground | -- | P0411 | -- | -- |
Pump Relay Coil Supply | P0102, P0412, P0418, | P0418 | P0690 | -- |
Pump Relay Control | P0418 | P0418 | P0411, P0418, P0690, P2431 | -- |
Pump Relay Switch Supply | P0411 | P0411 | -- | -- |
Solenoid Relay Coil Supply | P0412 | P0411, P0412 | P0690 | -- |
Solenoid Relay Control | P0412 | P0411, P0412 | P0411, P0412, P0690 | -- |
Solenoid Relay Switch Supply | P0411 | P0411 | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Key ON, Engine OFF Parameter Normal Range: BARO | |||
5-Volt Reference Voltage | 41 kPa | 41 kPa | 111 kPa |
Pressure Sensor Signal | 41 kPa | 41 kPa | 145 kPa |
Low Reference | BARO | 145 kPa | -- |
Circuit/System Description
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 solenoid 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 engine control module (ECM) 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:
| • | DTCs P0411 and P2430 run during Phase 1 |
| • | DTCs P2430 and P2440 run during Phase 2 |
| • | DTC P2444 runs during Phase 3 |
In all 3 phases, testing is accomplished by comparing the measured pressure against the expected pressure. The ECM 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.
Conditions for Running the DTC
| • | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0201-P0208, P0300, P0351-P0358, P0411, P0412, P0418, P0420, P0606, P0641, P0651, P2430, P2431, P2432, P2433, 2444 are not set. |
| • | The system voltage is 11-18 volts. |
| • | The start-up engine coolant temperature (ECT) is between 5-80°C (41-176°F). |
| • | The start-up intake air temperature (IAT) is greater than 5°C (41°F). |
| • | The BARO is greater than 70 kPa. |
| • | The MAF sensor is less than 33 g/s. |
| • | DTC P2440 runs once per trip start up when the above conditions are met and AIR pump operation is requested. |
| • | AIR system is commanded ON. |
| • | Conditions are stable for greater than 5 seconds. |
Conditions for Setting the DTC
| • | The ECM determines that the actual AIR system pressure is 3 kPa less than the predicted AIR system pressure. |
| • | DTC P2440 sets during phase 2 when the above condition is met for greater than 2 seconds. |
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.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Verify that DTCs P0412, P0418, P0641, P0651, P2430, P2431, P2432, P2433 or P2444 are not set.
- Ignition ON, enable and disable the AIR solenoid relay and observe that the solenoid valve operates.
- Inspect the AIR hoses/pipes between the pump and the shut-off valve for leaks.
- Engine running, enable the AIR pump relay and observe that the AIR Pressure Sensor parameter increases to approximately 15-22 kPa above BARO.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
| ⇒ | If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. |
Circuit/System Testing
- Disconnect the harness connector at the AIR solenoid valve.
- Ignition ON, connect a test lamp between the AIR solenoid voltage supply terminal 6 and the solenoid ground circuit terminal 4, the test lamp should not illuminate.
- Inspect the AIR pump inlet and outlet hoses/pipes for leaks or restrictions.
- Inspect the AIR solenoid valve for leaks.
| ⇒ | If the test lamp illuminates, test the AIR solenoid supply voltage circuit for a short to voltage. If the circuit tests normal, test or replace the AIR solenoid relay. |
| ⇒ | If the solenoid valve tests normal, replace the AIR pump. |
Component Testing
AIR Solenoid Static Test
Measure the AIR solenoid for a resistance of 4.8-6.8 ohms across the B+ terminal 6 and the ground terminal 4 at the AIR solenoid valve at an ambient temperature of approximately 20°C (68°F).
| ⇒ | If the resistance is not within range, replace the AIR solenoid valve assembly. |
AIR Solenoid Test
Install a 10A fused jumper wire between the battery voltage supply terminal and 12 volts. Install a jumper wire between ground terminal at the solenoid valve and ground. The AIR solenoid valve should open when the jumper is connected to ground and close when the jumper is removed from ground.
| ⇒ | If the solenoid valve does not perform as specified, replace the AIR solenoid valve and assembly. |
Relay Test
- Test between the normally closed switch terminals, if any, for 0 ohms.
- Test between the normally open switch terminals for infinite ohms.
- Test between each switch terminal and either coil terminal for infinite ohms.
- Connect the relay coil terminals to ground and fused power to energize the relay.
- Test between each switch terminal and each coil terminal for 0 volts.
- Test between the normally closed switch terminals, if any for infinite ohms.
- Test between the normally open switch terminals for 0 ohms.
Repair Instructions
| • | Control Module References for ECM replacement and programming |
Repair Verification
- Ignition ON, enable and disable the AIR solenoid relay and observe that the AIR solenoid valve operates.
- Engine running, enable the AIR pump relay and observe that the AIR Pressure Sensor parameter increases to approximately 15-22 kPa above BARO.
