P0410

Circuit Description
A Secondary Air Injection (AIR) pump is used on this vehicle to lower tailpipe emissions on start-up. The VCM supplies a ground to the AIR pump relay control circuit. This energizes the AIR pump relay and supplies voltage to the AIR pump clutch. The VCM uses the HO2S voltages and the short term fuel trim to diagnose the Secondary Air Injection System.

The VCM monitors the HO2S voltages and the short term fuel trim value when the AIR pump is energized. This additional air causes the HO2S voltages to shift low, reflecting the leaner mixture. The short term fuel trim should increase above 128 confirming that the VCM is supplying additional fuel. The low HO2S voltages and higher short term fuel trim value provide confirmation that the secondary air injection system is operating properly. When the AIR pump is de-energized, the HO2S voltages should increase and begin switching normally.

This DTC is set when the VCM determines that the HO2S voltages for both banks did not respond as expected during this test. If only one HO2S responded as expected, the VCM sets either a DTC P1415 or P1416 depending on which engine bank the AIR system is inoperative.

Conditions for Running the DTC
^ No active secondary AIR DTCs
^ No active CMP sensor DTCs
^ No active ECT sensor DTCs
^ No active EGR DTCs
^ No active fuel trim DTCs
^ No active IAC DTCs
^ No active IAT sensor DTCs
^ No active MAF sensor DTCs
^ No active MAP sensor DTCs
^ No active HO2S DTCs
^ No active transmission DTCs
^ No active EVAP system DTCs
^ No active TP sensor DTCs
^ No active VS sensor DTCs
^ No active misfire DTCs
^ The commanded air/fuel ratio is 14.7:1
^ The system voltage is greater than 10 volts
^ The engine speed is greater than 550 RPM
^ The engine load is less than 50%
^ The MAF is less than 100 g/s
^ The system has been in closed loop operation for more than 15 seconds
^ The IAT is greater than 0°C (32°F)
^ The ECT is between 75°C and 105°C (167°F to 221°F)

Conditions for Setting the DTC
The HO2S voltage remains above 299 mV or the change in the short term fuel trim value is less than a calibrated value.

Action Taken When the DTC Sets
^ The Control Module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
^ The Control Module will set the DTC and records the operating conditions at the time the diagnostic fails. The Control Module stores the failure information in the scan tools Freeze Frame and/or the Failure Records.

Conditions for Clearing the MIL/DTC
^ The Control Module turns OFF the MIL after 3 consecutive drive trips when the test has Run and Passed.
^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the Engine Coolant Temperature is more than 70°C (158°F) during the same ignition cycle).
^ Use the scan tool Clear Information function.

Diagnostic Aids
Low AIR System volume may cause a DTC P1415, P1416 or an intermittent complaint. Also check for the following conditions:
^ Pinched, kinked or restricted AIR pipes, hoses or fittings
^ Leaks, holes, loose fittings or hoses
^ Restricted or obstructed AIR pump inlet
^ Leaks or restrictions in the vacuum hoses for the AIR Shut Off Valve.

An AIR supply hose that is melted before the check valve could indicate exhaust gas back-flow past the check valve.

An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. Symptom Related Diagnostic Procedures

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. This step will determine if the AIR System is functioning correctly.
12. This step will determine if the VCM is capable of controlling the AIR Pump Relay.
15. This step is to check for a short to voltage on the control circuit.
16. The engine must be running for this test to ensure a vacuum supply to the system.
17. This step will determine if the AIR Pump is capable of producing airflow.
29. An open fuse for the battery feed circuit could be caused by a short to ground in the components operated by the relay. Also check the wiring in the circuits on the switched side of the relay. Refer to Diagnostic Aids.