GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Yukon XL - 4WD 🢒 Engine 🢒 Engine Controls - 8.1L 🢒 DTC P0410

Circuit Description

An secondary air injection (AIR) pump is used on this vehicle to lower tail pipe emissions on start-up. The powertrain control module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump and the AIR solenoid valve. Engine vacuum is applied to the AIR shut-off valve when the AIR solenoid is energized. The engine vacuum opens the AIR shut-off valve which allows AIR to flow to the exhaust manifolds.

The PCM monitors the heated oxygen sensor (HO2S) voltages to diagnose the AIR system.

During the AIR test, the PCM activates the AIR pump during Closed Loop operation. When the AIR system is activated, the PCM monitors the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.

If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 or P1416 to indicate on which bank the AIR system is inoperative.

Conditions for Running the DTC
    • DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0131, P0151, P0132, P0133, P0134, P0135, P0141-P0155, P0161, P0171, P0172, P0174, P0175, P0200, P0300, P0335, P0336, P0351-P0358, P0443, P0446, P0449, P1120, P1220, P1221, or P1258 are not set.
    • The start-up engine coolant temperature (ECT) is below 80°C (176°F).
    • The engine run time is more than 2 seconds.
    • The throttle position (TP) sensor angle is not moving more than 1 percent.
    • The engine load is less than 23 percent.
    • The engine air flow is less than 18 g/s.
    • The engine speed is more than 750 RPM.
    • The ignition voltage is more than 11.7 volts.
    • The air fuel ratio is 14.7:1.
    • The ECT is between 70-110°C (158-230°F).
    • The intake air temperature (IAT) is more than 2°C (36°F).
    • The fuel system is not operating in power enrichment or deceleration fuel cut-off.
    • The short term fuel trim is in cells 5 or 6.
    • The vehicle speed is more than 25 km/h (15 mph).

Conditions for Setting the DTC
    • The HO2S voltage does not go below 222 mV within 1.2 seconds when the AIR pump turns ON during Closed Loop operation.
    • The short term fuel trim does not go above a predetermined amount when the AIR pump turns ON during Closed Loop operation.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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
    • Using Freeze Frame/Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining how many ignition cycles the diagnostic reported a pass or a fail. Operate the vehicle within the same Freeze Frame conditions, such as RPM, load, vehicle speed, temperature etc., that you observed. This will isolate when the DTC failed.
    • For an intermittent, refer to Intermittent Conditions .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. If DTC P0418 sets, this indicates the control side of the relay is not operating. Vacuum lines that are reversed on the AIR solenoid causes this DTC to set.

    2.

  2. The AIR MaxiFuse is located in the underhood electrical center.

    3.

  3. The AIR pump relay is located near the AIR pump.

    4.

  4. Inspect for intermittent shorts to ground if the AIR pump functions properly.

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: Ensure the vacuum source is on the proper side of the AIR solenoid before proceeding. The vacuum source port is on the same side as the mounting bracket.

Is DTC P0418 set?

Go to DTC P0418

Go to Step 3

3

Is the AIR MaxiFuse® OK?

Go to Step 4

Go to Step 12

4
  1. Install the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Enable the AIR pump using a scan tool in output controls.

Does the AIR pump turn ON?

Go to Step 9

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the AIR pump relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the AIR pump relay B+ supply circuit terminal, on the switch side of relay, using the test lamp connected to a ground. Refer to Using Connector Test Adapters in Wiring Systems.

Is the test lamp illuminated?

Go to Step 6

Go to Step 18

6

Jumper the B+ terminal to the AIR pump feed circuit at the relay harness connector using a fused jumper wire. Refer to Using Fused Jumper Wires in Wiring Systems.

Does the AIR pump turn ON?

Go to Step 24

Go to Step 7

7
  1. The jumper is still installed.
  2. Disconnect the AIR pump electrical connector.
  3. Probe terminal A of the AIR pump electrical connector using the test lamp connected to battery ground. Refer to Using Connector Test Adapters in Wiring Systems.

Is the test lamp illuminated?

Go to Step 8

Go to Step 19

8
  1. The jumper is still installed.
  2. Connect the test lamp from the AIR pump supply voltage circuit to the ground circuit of the AIR pump harness connector.

Is the test lamp illuminated?

Go to Step 27

Go to Step 20

9

Did the AIR solenoid valve turn ON when the AIR system was enabled?

Go to Step 15

Go to Step 10

10
  1. Disconnect the AIR solenoid valve harness connector.
  2. Probe terminal A of the harness connector with the test lamp connected to battery ground. Refer to Using Connector Test Adapters in Wiring Systems.
  3. Enable the AIR pump using a scan tool in output controls.

Does the test lamp illuminate?

Go to Step  11

Go to Step 22

11
  1. Connect the test lamp from the AIR solenoid supply voltage circuit to the ground circuit of the AIR solenoid valve harness connector.
  2. Enable the AIR pump using a scan tool in output controls.

Does the test lamp illuminate?

Go to Step 25

Go to Step 20

12
  1. Turn OFF the ignition.
  2. Disconnect the electrical connectors from the following components:
    3. • The AIR pump
    • The AIR pump relay
    • The AIR solenoid valve
  3. Remove the AIR MaxiFuse® from the underhood electrical center.
  4. Probe the battery feed terminal for the AIR pump relay harness connector with the test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 21

Go to Step 13

13

Probe the AIR pump and AIR solenoid feed circuit at the AIR pump relay harness connector using the test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 23

Go to Step 14

14
  1. Turn OFF the ignition.
  2. Re-install the following components and electrical connector:
    3. • A new AIR MaxiFuse®
    • The AIR pump relay
    • The AIR solenoid
  3. Turn ON the ignition, with the engine OFF.
  4. Turn ON the AIR pump using the scan tool in the output controls.

Does the AIR MaxiFuse® open?

Go to Step 26

Go to Step 28

15
  1. Start the engine.
  2. Disconnect the vacuum harness from the AIR solenoid valve.
  3. Connect a vacuum gauge to the vacuum source.

Is an engine vacuum displayed on the vacuum gauge?

Go to Step 16

Go to Step 29

16
  1. Reconnect only the vacuum source to the AIR solenoid valve.
  2. Connect a vacuum gauge to the other port of the AIR solenoid valve.
  3. Enable the AIR pump using the scan tool in the output controls.

Is an engine vacuum indicated on the vacuum gauge when the AIR pump is enabled?

Go to Step 17

Go to Step 26

17
  1. Reconnect the vacuum harness to the AIR solenoid valve.
  2. Disconnect the air outlet hose from the AIR shut-off valve.
  3. Enable the AIR pump using the scan tool in the output controls.

Is air present at the outlet of the AIR shut-off valve?

Go to Step 30

Go to Step 31

18

Repair the open circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 33

--

19

Repair the open circuit between the AIR pump and the AIR relay. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 33

--

20

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

Is the action complete?

Go to

Step 33

--

21

Repair the short to ground in the ignition feed circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 33

--

22

Repair the open circuit in the circuit between the AIR solenoid and the AIR pump relay. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 33

--

23

Repair the short to ground in the circuit between the AIR pump relay and the AIR pump and solenoid. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 33

--

24

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

Is the action complete?

Go to Step 33

--

25
  1. Inspect for poor connections at the AIR solenoid valve electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair the poor connection as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 26

26

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

Is the action complete?

Go to Step 33

--

27
  1. Inspect for poor connections at the AIR pump electrical connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
  2. Repair the poor connection as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 28

28
  1. Connect the AIR pump electrical connector.
  2. Turn ON the AIR pump using a scan tool in the output controls.

Does the AIR pump MaxiFuse® open?

Go to Step 32

Go to Diagnostic Aids

29

Important: Inspect the vacuum check valve for proper installation. The tapered side of the check valve goes toward the vacuum source. Also inspect for vacuum with the check valve removed from the vacuum line. If there is vacuum, replace the check valve.

Repair the vacuum source.

Is the action complete?

Go to Step 33

--

30

Repair the restriction or for an AIR hose that is not connected at the point where the AIR system branches to both sides.

Is the action complete?

Go to Step 33

--

31

Replace the AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve Replacement .

Is the action complete?

Go to Step 33

--

32

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

Is the action complete?

Go to Step 33

--

33
  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 34

Go to Step 2

34

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