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DTC P0411/16795 - Secondary Air Injection System Incorrect Flow Detected

NOTE: DTC sets if Electronic Control Module (ECM) senses Secondary Air Injection (SAI) pump functioning, but quantity of air is recognized as insufficient by Heated Oxygen Sensor (HO2S).
  1. Turn ignition off. Disconnect SAI solenoid valve connector. Disconnect ECM connector. Connect Test Box (VAG 1598/18) to ECM wiring harness. Terminal assignments of test box are identical to ECM connector's.
  2. Using DVOM, check resistance between solenoid valve connector terminal No. 1 and test box socket No. 50. Resistance should be less than 1.5 ohms. If resistance is as specified, go to next step. If resistance is not as specified, locate and repair open circuit between solenoid valve connector and ECM. Erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to step 10).
  3. Reconnect solenoid valve connector. Disconnect a vacuum hose from solenoid valve and connect an auxiliary hose. Turn ignition on. Jumper test box sockets No. 1 and 6. Briefly jumper test box socket No. 50 to ground while blowing into auxiliary hose. Go to next step.
  4. Solenoid valve must open while activated and close when deactivated. If solenoid valve does not operate as specified, replace solenoid valve. Erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to step 10). If solenoid valve operates as specified, go to next step.
  5. Remove SAI pump pressure hose at engine. Check pressure hose for damage, replace if necessary. If hose is replaced, erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to step 10). If hose is not replaced, go to next step.
  6. Turn ignition on. Jumper test box sockets No. 1 and 6. Briefly jumper test box socket No. 49 to ground to activate SAI pump and go to next step.
  7. While SAI pump is activated, check for air pressure at pump. If pump runs but no air pressure is present, replace pump. Erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to step 10). If air pressure is present, go to next step.
  8. Check whether solenoid valve-to-combination valve vacuum hose is damaged or disconnected. If hose is okay, go to next step. Repair vacuum hose if necessary. Erase DTC memory and test drive vehicle. See CLEARING DTCS  in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to step 10).
  9. Connect hand-held vacuum pump to vacuum hose at combination valve. Start engine and let it idle. Operate hand-held vacuum pump several times. Combination valve must open and a noise change must be distinctly audible. If valve does not operate as specified, go to next step. If valve operates as specified, go to step 11).
  10. Replace faulty combination valve. Erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, go to next step.
  11. Replace faulty ECM. Erase DTC memory and test drive vehicle. See CLEARING DTCS in this article. Recheck DTC memory and verify DTC does not reset. If DTC resets, repeat testing procedure.
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