Circuit Description
An 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.
The PCM monitors the heated oxygen (HO2S) sensor 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 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 1 sensor responded, the PCM sets either a DTC P1415 for bank 1 or P1416 for bank 2 in order to indicate on which bank the AIR system is inoperative.
Conditions for Running the DTC
| • | DTCs P0101-P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0171-P0175, P0200, P0300, P0335, P0336, P0351-P0358, P0440, P0442, P0443, P0446, P0449, P1120, P1220, P1221, P1258, P1441, and the HO2S DTCs are not set. |
| • | The engine is running for more than 30 seconds. |
| • | The maximum air flow is 22 g/s. |
| • | The air/fuel ratio is 13.125:1. |
| • | The engine load is less than 40 percent. |
| • | The ignition voltage is more than 11.7 volts. |
| • | The engine is not operating in the Power Enrichment, the Decel Fuel Shut-off, or the Catalyst Over-Temperature Modes. |
| • | The engine speed is more than 850 RPM. |
| • | The engine coolant temperature (ECT) is between -10°C (+14°F) and 110°C (230°F). |
| • | The intake air temperature (IAT) is between -10°C (+14°F) and 100°C (212°F) . |
| • | The fuel system is operating in fuel trim cells 1, 2, 4, 5, or 6. |
Conditions for Setting the DTC
The HO2S voltage does not go below 222 mV for 1.3 seconds.
OR
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
| • | Remove any debris from the powertrain control module/throttle actuator control module (PCM/TAC) connector surfaces before servicing the PCM/TAC module. Inspect the PCM/TAC module connector gaskets when diagnosing or replacing the modules. Verify that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM/TAC modules. |
| • | For any test that requires probing the PCM or probing a component harness connector, use the connector test adapter kit J 35616 . Using this kit prevents damage to the harness or component terminals. Refer to Using Connector Test Adapters in Wiring Systems. |
| • | Carbon build-up in the exhaust manifold may restrict the amount of air flow 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 . |
| • | Excessive exhaust system back pressure |
| • | Moisture, water, or debris ingestion into the AIR pump |
| • | Leaking check valves will leave traces of exhaust carbon in the AIR system. |
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 |
Does the HO2S voltage drop below the specified value? | 222 mV | Go to Diagnostic Aids | Go to Step 3 | ||||||||
Inspect all hoses and pipes for:
Did all the above verify to be OK? | -- | Go to Step 4 | Go to Step 6 | |||||||||
4 |
Is air present at the hose outlet? | -- | Go to Step 7 | Go to Step 5 | ||||||||
5 | Repair the restriction or the blockage in the applicable bank AIR hoses/pipes between the exhaust manifold and the point where the system branches to both sides of the engine. Did you complete the repair? | -- | Go to Step 8 | -- | ||||||||
6 | Repair the condition found. Did you complete the repair? | -- | 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 | |||||||||
