GM Service Manual Online
For 1990-2009 cars only

Description

The control module activates the secondary air Injection (AIR) system by grounding both the pump relay and the vacuum control solenoid control circuits simultaneously. This energizes the AIR pump and the vacuum control solenoid. Vacuum is then applied, opening the valves. The pump then forces fresh air into the exhaust stream in order to accelerate catalyst operation. The control module will run up to 3 diagnostic tests using the pre-catalyst heated oxygen sensor (HO2S) voltage and Short Term FT to diagnose the system. The system can be diagnosed during normal secondary air injection operation or the control module can activate the system specifically for diagnostic purposes. If an air flow condition is detected, this diagnostic trouble code (DTC) will set. When inactive, the system prevents air flow in either direction.

Conditions for Running the DTC

    • DTCs P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0171, P0172, P0300, P0440, P0442, P0443, P0446, P0449, P0506, P0507, P1111, P1112, P1114, P1115, P1121, P1122, P1133, or P1134 are not set.
    • The engine run time is more than 10 seconds.
    • The engine coolant temperature (ECT) is between 4.5-110°C (40-230°F).
    • The mass air flow (MAF) is between 2-25 g/s.
    • The ignition voltage is more than 10 volts.
    • The engine speed is more than 800 RPM.
    • The fuel system is operating in DECEL control cell.
    • The intake air temperature (IAT) is between 4.5-70°C (40°-158°F).
    • The short term fuel trim is between 0.97-1.03.
    • The engine load is between 5-30 percent.
    • The barometric pressure (BARO) is above 75 kPa.
    • The vehicle speed is more than 40 km/h (25 mph).

Conditions for Setting the DTC

    • The pre-catalyst HO2S voltage remains above a predetermined lean value during the test.
        AND
    • The Short Term FT does not increase a calibrated amount during the test.
    • Both conditions above exist for 3 consecutive tests.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Diagnostic Aids

If the condition is intermittent, refer to Symptoms - Engine Controls .

If the DTC cannot be duplicated and is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set. Also refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

A short to voltage in the pump relay control circuit can result in the AIR pump running continuously with the ignition OFF by backfeeding to ground. This will eventually result in pump failure.

An AIR pump that had become inoperative and had shown indications of having exhaust gases in the outlet port would indicate check valve failure.

Test Description

The number below refers to the step number on the diagnostic table.

  1. The replacement PCM must be programmed.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Important: If DTC P0412 or DTC P0418 is also set, refer to the applicable DTC first.

Inspect for the following conditions:

    • Damage
    • Loose or restricted AIR pipes or hoses
    • Loose or restricted vacuum lines

Did you find and correct the condition?

Go to Step 42

Go to Step 3

3

  1. Turn ON the ignition.
  2. With a scan tool, command the AIR pump relay ON and OFF.

Does the pump turn ON and OFF with each command?

Go to Step 4

Go to Step 10

4

With a scan tool, command the AIR solenoid ON and OFF.

Does the solenoid turn ON and OFF with each command?

Go to Step 5

Go to Step 14

5

  1. Disconnect the AIR hose from the shut-off valve (pump side).
  2. With a scan tool, command the AIR pump ON.

Is airflow present at the hose outlet?

Go to Step 6

Go to Step 16

6

  1. Disconnect the vacuum line (source) from the solenoid.
  2. Start the engine.

Is vacuum present at the vacuum line?

Go to Step 7

Go to Step 24

7

  1. Reconnect the vacuum line to the solenoid.
  2. Disconnect the vacuum line from the shut-off valve.
  3. Start the engine.
  4. With a scan tool, command the AIR solenoid ON.

Is vacuum present at the vacuum line?

Go to Step 8

Go to Step 17

8

  1. Remove the shut-off valve from the vehicle.
  2. Install a hand held vacuum pump to the valve.
  3. Apply 33 kPa (10 in Hg) to valve.

Does the valve hold vacuum for 1 minute?

Go to Step 9

Go to Step 33

9

Important: Attempt to blow through the valve without vacuum applied. If you can blow through the valve, refer to Step 33.

  1. Leave the vacuum applied to the valve.
  2. Attempt to blow through the valve from the inlet side.

Can you blow through the valve?

Go to Step  25

Go to Step  33

10

Does the pump run continuously?

Go to Step 18

Go to Step 11

11

  1. Disconnect the pump relay.
  2. Turn ON the ignition.
  3. Probe the relay feed circuits using a test lamp that is connected to a good ground.

Does the test lamp illuminate when probing both circuits?

Go to Step 12

Go to Step 20

12

  1. Probe the relay control circuit using a test lamp that is connected to B+.
  2. Using a scan tool, command the pump ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 13

Go to Step 23

13

  1. Install a jumper wire between the relay switch feed and the pump feed.
  2. Turn ON the ignition.

Does the pump operate?

Go to Step  34

Go to Step  26

14

  1. Disconnect the solenoid.
  2. Turn ON the ignition.
  3. Probe the solenoid feed using a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step  15

Go to Step  20

15

  1. Probe the solenoid control circuit using a test lamp that is connected to B+.
  2. With a scan tool, command the solenoid ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step  36

Go to Step  23

16

  1. Disconnect the AIR hose from the pump.
  2. With a scan tool command the AIR pump ON.

Is airflow present at the pump outlet?

Go to Step  25

Go to Step  39

17

Inspect the vacuum line from the solenoid to the valve for a restriction or a loose condition.

Did you find and correct the condition?

Go to Step 42

Go to Step 37

18

  1. Ensure the ignition is ON.
  2. Disconnect the relay.

Does the pump stop operating?

Go to Step 19

Go to Step 28

19

  1. Probe the relay control circuit using a test lamp that is connected to B+.
  2. With a scan tool, command the pump ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 35

Go to Step 29

20

Inspect the feed fuse or fuses.

Is the fuse or fuses OK?

Go to Step 30

Go to Step 21

21

Test the feed circuit corresponding to the blown fuse or fuses for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 42

Go to Step 22

22

Test the pump feed for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 42

Go to Step 39

23

Is the test lamp ON steady?

Go to Step 29

Go to Step 32

24

Repair the vacuum source.

Did you complete the repair?

Go to Step 42

--

25

Repair the pipe, hose or check valve for an open or a restriction.

Did you find and correct the condition?

Go to Step 42

Go to Restricted Exhaust in Engine Exhaust

26

  1. Ensure the ignition is ON.
  2. Leave the jumper wire installed.
  3. Disconnect the pump.
  4. Connect a test lamp between the feed and ground circuits at the pump harness connector.

Does the test lamp illuminate?

Go to Step 38

Go to Step 27

27

  1. Ensure the ignition is ON.
  2. Leave the jumper wire installed.
  3. Disconnect the pump.
  4. Connect a test lamp between the feed and a good ground.

Does the test lamp illuminate?

Go to Step 31

Go to Step 30

28

Repair the short to voltage in the pump feed circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 42

--

29

Test for a short to ground in the control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 42

Go to Step 41

30

Repair the open pump feed circuit. Refer to Wiring Repairs in Wiring Repairs.

Did you complete the repair?

Go to Step 42

--

31

Repair the open ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 42

--

32

Important: If diagnosis reveals a short to voltage in the AIR pump relay control circuit, be sure to check AIR pumps. Refer to Diagnostic Aids.

Test for an open or short to voltage in the control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 42

Go to Step 40

33

Repair the valve. Refer to Secondary Air Injection Shutoff Valve Replacement .

Did you complete the repair?

Go to Step 42

--

34

Test for poor connections at the relay. 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 42

Go to Step 35

35

Replace the relay.

Did you complete the repair?

Go to Step 42

--

36

Test for poor connections at the solenoid. 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 42

Go to Step 37

37

Replace the solenoid. Refer to Secondary Air Injection Vacuum Control Solenoid Valve Replacement .

Did you complete the repair?

Go to Step 42

--

38

Test for poor connections at the pump. 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 42

Go to Step 39

39

Important: After you have replaced the pump, turn ON the ignition with the engine OFF. If the pump runs without a scan tool command, refer to Step 18.

Replace the pump. Refer to Secondary Air Injection Pump Replacement .

Did you complete the repair?

Go to Step 42

--

40

Test for poor connections 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 42

Go to Step 41

41

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

Go to Step 42

--

42

  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 as specified in the supporting text.

Does the DTC run and pass?

Go to Step 43

Go to Step 2

43

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

System OK