Circuit Description
The secondary air injection (AIR) pump used on this vehicle lowers tail pipe emissions during start-up. The AIR system consists of the following items:
| • | The AIR pump |
| • | The shut-off valves |
| • | The vacuum control solenoid valve |
| • | The system hoses and pipes |
| • | The AIR relay, fuses, and related wiring |
The powertrain control module (PCM) uses the AIR relay to control the AIR pump. The PCM also controls the AIR vacuum control solenoid valve that supplies vacuum to the AIR shut-off valves. With the AIR system inactive, the AIR shut-off valves prevent air flow in either direction. With the AIR system active, the PCM applies ground to the AIR relay, and the vacuum control solenoid valve. Fresh air flows from the pump, through the system hoses, pass the shut-off valves, and into the exhaust stream. The air helps the catalyst to quickly get to a working temperature, thus lowering the tail pipe emissions on a start-up. The PCM tests the following AIR system components:
| • | The overall AIR system, including both banks--any problems detected here will result in DTC P0410. |
| • | The AIR system bank 1 (DTC P1415) |
| • | AIR system bank 2 (DTC P1416) |
| • | AIR relay (DTC P0418) |
| • | AIR vacuum control solenoid valve (DTC P0412) |
The PCM runs two tests to diagnose the AIR system: Passive, and Active. Both tests involve a response from the fuel control heated oxygen sensor (HO2S), (HO2S bank 1 sensor 1 and HO2S bank 2 sensor 2). The Passive test consists of two parts. If both passive tests pass, the PCM takes no further action. If either part of the passive test fails, or is inconclusive, the PCM initiates the Active tests. If the PCM determines that HO2S bank 2 sensor 1 did not respond as expected during the tests, DTC P1416 will set. For further information concerning the AIR system and system tests, refer to Secondary Air Injection System Description .
Conditions for Running the DTC
Passive Tests:
| • | The engine is running. |
| • | 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 0-108°C (32-226°F). |
| • | The intake air temperature (IAT) is between 0-60°C (32-140°F). |
| • | The power enrichment, or deceleration fuel cut-off (DFCO) is not active. |
Active Tests:
| • | The engine is running. |
| • | 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 evaporative emission (EVAP) purge is active. |
| • | The ECT is above 68°C (154°F). |
Conditions for Setting the DTC
Passive Tests :
| • | During the operation of the AIR pump, HO2S bank 2 sensor 1 voltage remains above 470 mV for 20 seconds (450 mV for 7 seconds on a hot start). |
| OR |
| • | With the AIR pump commanded OFF, HO2S bank 2 sensor 1 voltage remains below 700 mV for 25 seconds. |
| • | The PCM initiates the active test due to a failed or an indeterminate passive test. |
Active Test:
| • | A failed or an indeterminate passive test |
| • | The HO2S bank 2 sensor 1 voltage remains above 35 mV. |
| • | The PCM detects a failed passive test and two failed active tests. |
| OR |
| • | The PCM records an indeterminate passive test and three 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
If the condition is intermittent, refer to Intermittent Conditions .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Value(s) | 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? | 350 mV | Go to Diagnostic Aids | Go to Step 3 | ||||||||||
3 |
Does the vacuum gauge indicate vacuum? | -- | Go to Step 4 | Go to Step 5 | ||||||||||
4 | Inspect all pipes/hoses for:
Did you locate the condition? | -- | Go to Step 6 | Go to Step 7 | ||||||||||
5 | Replace the vacuum line between the AIR solenoid valve and the bank 2 AIR shut-off valve. Did you complete the replacement? | -- | Go to Step 8 | -- | ||||||||||
6 | Repair the condition. Refer to Secondary Air Injection Pump Intermediate Pipe/Hose Replacement - Bank 1 , Secondary Air Injection Pump Intermediate Pipe/Hose Replacement - Bank 2 , or Secondary Air Injection Crossover Pipe/Hose Replacement . Did you complete the repair? | -- | Go to Step 8 | -- | ||||||||||
7 | Replace the bank 2 AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve 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 | |||||||||||
