Circuit Description
The Secondary Air Injection (AIR) system is designed to lower exhaust emission levels after engine start up. The AIR pump is commanded ON for a specific amount of time.
The powertrain control module (PCM) commands the AIR pump relay ON, by supplying a ground to the AIR pump relay control circuit. This action energizes the AIR pump which forces fresh air into the exhaust stream. The PCM also commands the AIR vacuum control solenoid valve ON by suppling a ground to the control circuit. With the AIR solenoid activated, engine vacuum is then applied to the AIR shut-off valves. Fresh air from the AIR pump then enters into the exhaust stream. The air that is introduced into the exhaust system accelerates catalyst operation reducing exhaust emission levels. When inactive, the shut-off valves prevent air flow in either direction.
After a warm start up the PCM can detect an AIR system air flow fault by monitoring the heated oxygen sensors (HO2S) and Short Term Fuel Trim (FT) values. This is called a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the diagnostic will proceed with an intrusive or active tests. The PCM will command the AIR system ON during Closed Loop operation. The active test will pass or fail based on the response from the HO2S sensors. The active test consist of three tests run at 3 second intervals. A lean HO2S response indicates that the secondary AIR system is functioning properly. An increasing Short Term FT value also indicates a normal functioning system. The secondary AIR diagnostic consists of the combination of the passive and the active tests. If the PCM detects that the HO2S and Short Term FT did respond as expected on either bank 1 or bank 2, DTC P1415 or P1416 sets.
| • | The AIR system dual bank failure--DTC P0410 sets. |
| • | The AIR system bank 1 failure--DTC P1415 sets. |
| • | The AIR system bank 2 failure--DTC P1416 sets. |
The AIR system consists of the following components:
| • | The AIR pump |
| • | The shut-off valves |
| • | The vacuum control solenoid valve |
| • | The system hoses and pipes |
| • | The AIR pump relay, the fuses, and the related wiring |
Conditions for Running the DTC
Passive Tests
| • | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141,P150, P0151, P0152, P0153, P0154, P0155, P0201 ,P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0335, P0336, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P0412, P0418, P0506, P0507, P1133, P1134 are not set. |
| • | The engine is running for more than 3 seconds. |
| • | The engine speed is more than 600 RPM. |
| • | The throttle is steady. |
| • | The engine load is less than 80 percent. |
| • | The system voltage is more than 10.5 volts. |
| • | The mass air flow (MAF) is less than 35 g/s. |
| • | The air/fuel ratio is more than 12.5:1. |
| • | The engine coolant temperature (ECT) is between 5-108°C (41-227°F). |
| • | The intake air temperature (IAT) is between 5-72.5°C (41-162.5°F). |
| • | The power enrichment, or deceleration fuel cut-off (DFCO) is not active. |
| • | The start-up ECT is between 5-80°C (41-176°F). |
Active Tests
| • | The engine is running for more than 3 seconds. |
| • | The engine speed is more than 600 RPM. |
| • | The throttle is steady. |
| • | The engine load is less than 80 percent. |
| • | The system voltage is more than 10.5 volts. |
| • | The MAF is less than 35 g/s. |
| • | The fuel system is in Closed Loop operation. |
| • | The EVAP purge is active. |
| • | The ECT is above 68°C (154°F). |
| • | The short term fuel trim is between -3 and +3 percent. |
| • | The fuel trim is in cells 4, 5, or 6. |
| • | The vehicle speed is between 56-72 km/h (25-45 mph). |
Conditions for Setting the DTC
Passive Tests
| • | When the AIR pump is commanded ON, the HO2S voltages for the applicable bank sensor is greater than remains 470 mV for 20 seconds, and above 200 mV for 7 seconds, on a warm start. |
| OR |
| • | With the AIR pump commanded OFF, the HO2S voltage for the applicable bank sensor does not toggle above 600 mV for 25 seconds, 7 seconds on a warm start. |
Active Tests
| • | A failed or an inconclusive passive test has occurred. |
| • | The HO2S voltage remains above 250 mV for three 3 second active tests. |
| • | The PCM detects a failed passive test and 2 failed active tests. |
| OR |
| • | The PCM records an inconclusive passive test and 3 failed active 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
Notice: Use the connector test adapter kit J 35616-A for any test that
requires probing the following items:
• The PCM harness connectors • The electrical center fuse/relay cavities • The component terminals • The component harness connector
| • | Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help to diagnose the condition. The information may help to determine how often the condition that set the DTC occurs. |
| • | Inspect for the following conditions: |
| - | A low AIR system air flow may cause this DTC to set. |
| - | Any excessive exhaust system back-pressure |
| - | Any moisture, water, or debris ingestion into the AIR pump. |
| - | Any restrictions in the AIR pump inlet, duct, or filter |
| - | An intermittent may be caused by any of the following conditions: |
| • | Any pinched hoses or vacuum lines |
| • | Any kinked pipes/hoses or vacuum lines |
| • | Any split pipes/hoses or vacuum lines |
| • | Any heat damaged pipes |
| • | Any deteriorated hoses or vacuum lines |
| • | Any reversed inlet and outlet hoses at the AIR pump may cause a reduced air flow. This condition may cause this DTC to set. The AIR pump inlet and outlet ports should be clearly identified on the pump. |
| • | An AIR solenoid stuck open or leaking vacuum internally may hold the shut-off valves open, an audible exhaust popping noise may be heard through the air pump inlet hose. This condition may not set a code and may cause the fuel trim parameters to indicate a high percentage value at an idle |
| • | The AIR solenoid vents the vacuum from the shut-off valves when the system is inactive. Verify proper connections of vacuum hoses, reversed connections at the AIR solenoid may cause the AIR shut-off valves to be held open. |
| • | When commanding the AIR System ON with a scan tool the PCM will activate the AIR pump and the AIR solenoid. The fuel control system will then enter Open Loop status. This action will allow fresh air to enter the exhaust stream and cause the HO2S mV parameter to drop to near 0 mV. This would indicate a properly operating AIR system. |
| • | However if the AIR pump does not operate or there is no air flow from the pump entering the exhaust stream due to a leak in the system, the HO2S parameter may still drop below 100 mV. This is due to the fresh air being drawn into the exhaust stream from the opening of the shut-off valves. The HO2S will respond with a drop in mV readings as a result of this air leaning out the exhaust. The voltages may decrease to below 100 mV but not approach 0 mV. |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
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-Engine Controls? | -- | Go to Step 2 | |||||||
2 |
Does the HO2S voltage drop below the specified value? | 350 mV | Go to Diagnostic Aids | Go to Step 3 | ||||||
3 | Perform a visual inspection of all hoes/pipes and vacuum lines for the following conditions:
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 4 | ||||||
4 |
Does the vacuum gage display a value greater than the specified value? | 33 kPa/10 in Hg | Go to Step 5 | Go to Step 10 | ||||||
5 |
Does the shut-off valve hold vacuum for the specified amount of time? | 1 Minute | Go to Step 6 | Go to Step 11 | ||||||
6 |
Does air flow freely at the intermediate hose? | -- | Go to Step 7 | Go to Step 8 | ||||||
7 |
Caution: Refer to Secondary Air Injection Check Valve Caution in the Preface section.
Does air flow freely from the shut-off valve? | -- | Go to Step 9 | Go to Step 11 | ||||||
8 | Repair the leak or restriction in one of the following components:
Did you complete the repair? | -- | Go to Step 12 | -- | ||||||
9 |
Caution: Refer to Secondary Air Injection Check Valve Caution in the Preface section. Replace the leaking or restricted shut-off valve outlet pipe. Refer to Secondary Air Injection Shut-Off Valve Outlet Pipe/Hose Replacement - Bank 1 or Secondary Air Injection Shut-Off Valve Outlet Pipe/Hose Replacement - Bank 2 . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
10 | Replace the vacuum line between the AIR solenoid valve and the applicable bank AIR shut-off valve. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
11 |
Caution: Refer to Secondary Air Injection Check Valve Caution in the Preface section. Replace the AIR shut-off valve for the applicable bank. Refer to Secondary Air Injection Shutoff Valve Replacement - Bank 1 or Secondary Air Injection Shutoff Valve Replacement - Bank 2 . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
12 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 13 | ||||||
13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||
