Circuit Description
A secondary air injection (AIR) pump is used on this vehicle in order to reduce the tail pipe emissions during start-up. The powertrain control module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump.
The PCM monitors the heated oxygen sensor (HO2S) voltages in order to diagnose the AIR system.
During the AIR test, the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages and monitors the 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 in order to indicate on which bank the AIR system is inoperative.
Conditions for Running the DTC
| • | DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0131-P0135, P0137, P0138, P0140, P0141, P0151-P0155, P0171-P0175, P0200, P0300, P0325, P0327, P0332, P0335, P0336, P0351-P0358, P0430, P0500, P0502, P0503, P1133, P1134, P1153, and P1154 are not set. |
| • | The engine operates for more than 30 seconds. |
| • | The engine run time is more than 20 seconds after closed loop operation. |
| • | The engine speed is more than 850 RPM. |
| • | The maximum air flow is 22 g/s. |
| • | The ECT is between -10°C (14°F) and 110°C (255°F). |
| • | The IAT is between -10°C (14°F) and 100°C (212°F). |
| • | The ignition voltage is more than 11.7 volts. |
| • | The engine load is less than 40 percent. |
| • | The air fuel ratio is 13.125:1. |
| • | The engine is not operating in power enrichment mode OR in deceleration fuel cut-off mode. |
| • | The short term integrators are monitored while in fuel trim cells 1, 2, 5, or 20. |
Conditions for Setting the DTC
| • | When the AIR pump turns ON during closed loop operation, the HO2S voltage does not go below 222 mV for 0.9 seconds. |
| • | When the AIR pump turns ON during closed loop operation, the short term fuel trim does not change more than a predetermined value. |
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
| • | An obstruction in the exhaust manifold may restrict the amount of air flow that is necessary to affect the HO2S voltage. If you suspect this condition, remove the air pipe from the manifold and inspect the passage. |
| • | For an intermittent condition, refer to Intermittent Conditions . |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
2 |
Important: Before proceeding with this diagnostic table, ensure that the AIR pump is operating and that air is present at the outlet of the AIR pump. If the AIR pump is inoperative, refer to DTC P0410 for further diagnosis.
Does the HO2S voltage drop below the specified value? | 350 mV | Go to Diagnostic Aids | Go to Step 3 | ||||||||
Inspect all hoses and pipes for:
Did you locate the condition? | -- | Go to Step 6 | Go to Step 4 | |||||||||
4 |
Is air pressure present at the hose outlet? | -- | Go to Step 7 | Go to Step 5 | ||||||||
5 | Repair the restriction or blockage in the applicable AIR hoses and pipes between the exhaust manifold and the point where the system branches to both sides of the engine. Is the action complete? | -- | Go to Step 8 | -- | ||||||||
6 | Repair the condition. Is the action complete? | -- | Go to Step 8 | -- | ||||||||
7 | Replace the applicable check valve. Refer to Secondary Air Injection Check Valve and Check Valve Pipe Replacement - Bank 1 or Secondary Air Injection Check Valve and Check Valve Pipe Replacement - Bank 2 . Did you complete the replacement? | -- | Go to Step 8 | -- | ||||||||
8 |
Does the DTC run and pass? | -- | Go to Step 9 | Go to Step 2 | ||||||||
9 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||||||
