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
| • | No active mass air flow (MAF) DTCs |
| • | No active manifold absolute pressure (MAP) DTCs |
| • | No active engine coolant temperature (ECT) DTCs |
| • | No active intake air temperature (IAT) DTCs |
| • | No active throttle position (TP) DTCs |
| • | No active HO2S DTCs |
| • | No active fuel trim DTCs |
| • | No active injector DTCs |
| • | No active crankshaft position (CKP) sensor DTCs |
| • | No active ignition control (IC) DTCs |
| • | No active misfire DTCs |
| • | No active evaporative emission (EVAP) DTCs |
| • | The engine run time is more than 2 seconds. |
| • | The TP sensor angle is not moving more than 1 percent. |
| • | The engine load is less than 43 percent. |
| • | The engine air flow is less than 22 g/s. |
| • | Engine speed is more than 900 RPM. |
| • | The ignition voltage is more than 11.4 volts. |
| • | The air fuel ratio is 14.7:1. |
| • | The ECT is more than -10°C (+14°F), but less than 110°C (230°F). |
| • | The 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. |
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. |
| • | 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 PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Diagnostic Aids
Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.
| • | 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 Symptoms . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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If DTC P0418 sets, this indicates the control side of the relay is not operating. Refer to DTC P0418 Secondary Air Injection (AIR) Pump Relay Control Circuit for further diagnosis. Vacuum lines that are reversed on the AIR solenoid causes this DTC to set.
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The AIR MaxiFuse® is located in the underhood electrical center.
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The AIR pump relay is located near the AIR pump.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | Go to Step 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 Secondary Air Injection (AIR) Pump Relay Control Circuit | Go to Step 3 | |||||||
Is the AIR MaxiFuse® OK? | Go to Step 4 | Go to Step 12 | |||||||
4 |
Does the AIR pump turn ON? | Go to Step 9 | Go to Step 5 | ||||||
Does the test lamp illuminate? | Go to Go to Step 6 | Go to Step 19 | |||||||
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 25 | Go to Step 7 | ||||||
7 |
Does the test lamp illuminate? | Go to Step 8 | Go to Step 20 | ||||||
8 |
Does the test lamp illuminate? | Go to Step 28 | Go to Step 21 | ||||||
9 | Did the AIR solenoid valve turn ON when the AIR system was enabled? | Go to Step 15 | Go to Step 10 | ||||||
10 |
Does the test lamp illuminate? | Go to Step 11 | Go to Step 23 | ||||||
11 |
Does the test lamp illuminate? | Go to Step 26 | Go to Step 21 | ||||||
12 |
Does the test lamp illuminate? | Go to Step 22 | 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 24 | Go to Step 14 | ||||||
14 |
Does the AIR MaxiFuse® open? | Go to Step 27 | Go to Step 29 | ||||||
15 |
Does an engine vacuum display on the vacuum gauge? | Go to Step 16 | Go to Step 30 | ||||||
16 |
Is an engine vacuum indicated on the vacuum gauge when the AIR pump is enabled? | Go to Step 17 | Go to Step 27 | ||||||
17 |
Is air present at the AIR outlet hose? | Go to Step 18 | Go to Step 33 | ||||||
18 |
Is air present at the outlet of the AIR shut-off valve? | Go to Step 32 | Go to Step 31 | ||||||
19 | Repair the open circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | Go to Step 34 | -- | ||||||
20 | Repair the open circuit between the AIR pump and the AIR relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
21 | Repair the faulty ground connection or the open ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
22 | Repair the short to ground in the ignition feed circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
23 | Repair the open circuit in the circuit between the AIR solenoid and the AIR pump relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 34 | -- | ||||||
24 | 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. Did you complete the repair? | Go to Step 34 | -- | ||||||
25 | Replace the AIR pump relay. Refer to Secondary Air Injection Pump Relay Replacement . Did you complete the replacement? | Go to Step 34 | -- | ||||||
26 |
Did you find and correct the condition? | Go to Step 34 | Go to Step 27 | ||||||
27 | Replace the AIR solenoid valve. Refer to Secondary Air Injection Solenoid Valve Replacement . Did you complete the replacement? | Go to Step 34 | -- | ||||||
28 |
Did you find and correct the condition? | Go to Step 34 | Go to Step 29 | ||||||
29 |
Does the AIR pump MaxiFuse® open? | Go to Step 33 | Go to Diagnostic Aids | ||||||
30 |
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. Did you complete the repair? | Go to Step 34 | -- | ||||||
31 | Repair the restriction or for an AIR hose that is not connected at the point where the AIR system branches to both sides. Did you find and correct the condition? | Go to Step 34 | -- | ||||||
32 | Replace the AIR shut-off valve. Refer to Secondary Air Injection Shutoff Valve Replacement . Did you complete the replacement? | Go to Step 34 | -- | ||||||
33 | Replace the AIR pump. Refer to Secondary Air Injection Pump Replacement . Did you complete the replacement? | Go to Step 34 | -- | ||||||
34 |
Does the scan tool indicate that this test passed? | Go to Step 35 | Go to Step 2 | ||||||
35 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | Go to the applicable DTC table | System OK |
