System Description
The DTC P2441 Secondary Air Injection (AIR) System Shut-Off Valve Stuck Closed diagnostic monitors the operation of the AIR shut-off valve. The secondary AIR system helps reduce exhaust emissions. 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 shut-off valve. The AIR shut-off valve controls the flow of air from the AIR pump to the exhaust manifold. The AIR solenoid valve supplies the manifold vacuum that is used to operate the AIR shut-off valve. A pressure sensor is used to monitor the air flow from the AIR pump. By comparing the measured pressure against the expected pressure the pressure sensor can detect faults in the AIR pump, AIR shut-off valve, and the AIR solenoid valve. The pressure sensor can also detect leaks in the secondary AIR system plumbing.
Conditions for Running the DTC
| • | The engine is running. |
| • | The secondary AIR solenoid valve is commanded ON. |
| • | DTC P2441 runs every time the above conditions have been met. |
Conditions for Setting the DTC
The pressure sensor does not detect exhaust gas pulsations when the AIR shut-off valve should be OPEN.
Action Taken When the DTC Sets
| • | The PCM turns OFF the MIL on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present. |
| • | The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL on the third consecutive trip cycle during which the diagnostic has been run and the fault condition is no longer present. |
| • | A DTC will clear after 40 consecutive warm-up cycles have occurred without a fault. |
| • | A DTC can be cleared by using the scan tool Clear Information function. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
-
This step verifies the operation of the secondary AIR solenoid valve.
-
This step verifies the correct operation of the secondary AIR shut-off valve.
-
This step verifies the operation of the vacuum check valve.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | ||
2 | Install a scan tool and check for DTCs. Is DTC P2430, P2431, P2432, or P2433 present? | -- | Go to Step 3 | |
Did the vacuum gage indicate pressure when the AIR pump was ON? | -- | Go to Step 8 | Go to Step 4 | |
4 |
Did the vacuum gage indicate pressure with the engine running? | -- | Go to Step 5 | Go to Step 10 |
5 |
Did the vacuum gage indicate pressure when the AIR pump was ON? | -- | Go to Step 12 | Go to Step 6 |
6 |
Did the test lamp illuminate? | -- | Go to Step 7 | Go to Step 14 |
7 |
Did the test lamp illuminate when the AIR solenoid valve and AIR pump were commanded ON? | -- | Go to Step 16 | Go to Step 13 |
Did the air pass through the AIR shut-off valve? | 45 kPa (13.3 in Hg) | Go to Step 9 | Go to Step 18 | |
9 |
Did you find and correct a condition? | -- | Go to Step 21 | Go to Intermittent Conditions |
10 | Inspect for the correct installation of the vacuum check valve. The BLACK side of the check valve should be towards the intake manifold. Did you find and correct a condition? | -- | Go to Step 21 | Go to Step 11 |
Did the check valve pass both tests? | -- | Go to Step 12 | Go to Step 15 | |
12 | Repair the leak, blockage, or restriction in the vacuum supply hose between the AIR solenoid valve and the intake manifold. Did you complete the repair? | -- | Go to Step 21 | -- |
13 |
Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 19 |
14 | Repair the open or short to ground in the ignition positive voltage circuit of the AIR solenoid valve. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 21 | -- |
15 | Replace the vacuum check valve. Did you complete the replacement? | -- | Go to Step 21 | -- |
16 | Test for an intermittent and for a poor connection at the AIR solenoid valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 17 |
17 | Replace the secondary AIR solenoid valve. Refer to Secondary Air Injection Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 21 | -- |
18 | Replace the secondary AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve Replacement . Did you complete the replacement? | -- | Go to Step 21 | -- |
19 | Test for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 20 |
20 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 21 | -- |
21 |
Did a DTC P2441 set? | -- | Go to Step 2 | Go to Step 22 |
22 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
