GM Service Manual Online
For 1990-2009 cars only

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 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 AIR 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 AIR system plumbing.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2441 Secondary Air Injection (AIR) System Shut-Off Valve Stuck Closed

Conditions for Running the DTC

    • DTC P0010, P0011, P0012, P0016, P0031, P0032, P0100, P0101, P0102, P0103, P0110, P0112, P0113, P0115, P0117, P0118, P0120, P0121, P0122, P0123, P0125, P0130, P0133, P0134, P0171, P0172, P0300, P0301-P0304, P0325, P0327, P0328, P0335, P0340, P0341, P0351-P0354, P0385, P0450, P0451, P0452, P0453, P2195, P2196, P2430, P2431, P2432, P2433, P2645, P2646, P2647 are not set.
    • The engine is running.
    • The 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 powertrain control module (PCM) illuminates the malfunction indicator lamp (MIL) during the second key cycle in which the DTC sets.
    • 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.

  1. The Diagnostic System Check - Vehicle 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.

  2. This step verifies the operation of the AIR solenoid valve.

  3. This step verifies the correct operation of the AIR shut-off valve.

  4. 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

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Install a scan tool and check for DTCs.

Is DTC P2430, P2431, P2432, or P2433 present?

--

Go to DTC P2430 , DTC P2431 , DTC P2432 , or DTC P2433

Go to Step 3

3

  1. Disconnect the vacuum hose at the secondary air injection (AIR) shut-off valve.
  2. Connect a vacuum gage to the vacuum hose.
  3. Start the engine.
  4. Command the AIR solenoid valve and the AIR pump ON with the scan tool. Refer to Scan Tool Output Controls .

Did the vacuum gage indicate pressure when the AIR pump was ON?

--

Go to Step 8

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the vacuum supply hose at the AIR solenoid valve.
  3. Connect the vacuum gage the vacuum supply hose.
  4. Start the engine.

Did the vacuum gage indicate pressure with the engine running?

--

Go to Step 5

Go to Step 10

5

  1. Turn OFF the ignition.
  2. Disconnect the other vacuum hose from the AIR solenoid valve and connect the vacuum gage to the vacuum port.
  3. Reconnect the vacuum supply hose to the AIR solenoid valve.
  4. Start the engine.
  5. Command the AIR solenoid valve and the AIR pump ON with the scan tool.

Did the vacuum gage indicate pressure when the AIR pump was ON?

--

Go to Step 12

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the electrical connector of the AIR solenoid valve.
  3. Connect a test lamp between the ignition positive voltage circuit of the AIR solenoid valve and a known good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.
  4. Turn ON the ignition, with the engine OFF.

Did the test lamp illuminate?

--

Go to Step 7

Go to Step 14

7

  1. Connect a test lamp between the ignition positive voltage circuit and the control circuit of the AIR solenoid valve. Refer to Troubleshooting with a Test Lamp in Wiring Systems.
  2. Command the AIR solenoid valve and the AIR pump ON with the scan tool.

Did the test lamp illuminate when the AIR solenoid valve and AIR pump were commanded ON?

--

Go to Step 16

Go to Step 13

8

  1. Turn OFF the ignition.
  2. Remove the AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve Replacement .
  3. Connect a hand vacuum pump to the vacuum hose port of the AIR shut-off valve.
  4. Apply the specified value of vacuum to the AIR shut-off valve.
  5. Blow air into the large port on the AIR pump side of the AIR shut-off valve.

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

  1. Test for a leak, a blockage, or a restriction in the air hose and pipe assembly from the AIR shut-off valve to the exhaust manifold.
  2. Repair as necessary.

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

11

  1. Remove the vacuum check valve.
  2. Connect a hand vacuum pump to the BLACK side of the check valve.
  3. Apply vacuum to the check valve. You should not be able to hold vacuum.
  4. Connect the hand vacuum pump to the other side of the check valve.
  5. Apply vacuum to the check valve. You should be able to hold vacuum.

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

  1. Test for an open in the control circuit of the AIR solenoid valve. Refer to Circuit Testing in Wiring Systems.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

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 AIR solenoid valve. Refer to Secondary Air Injection Solenoid Valve Replacement .

Did you complete the replacement?

--

Go to Step 21

--

18

Replace the 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 powertrain control module (PCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 21

--

21

  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC.

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?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK