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John, GMC Technician
Category: GM
Satisfied Customers: 9176
Experience:  ASE MASTER TECHNICIAN/40 years experience
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GMC Envoy My check engine light stays on and prevents a

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My "check engine" light stays on and prevents a passing inspection. The diagnostic reading is: DTC P0410: Secondary Air Injection (Air)System. The vacumn lines have been drained/checked. This did not help!! What are the steps to follow to resolve this problem? Thanks for your advice.

Hello & welcome to JA,


The p0410 is a fault code that sets when the computer does not recognize that the secondary air injection pump is running when the engine is cold to aid in a rich condition for "cold engine operation". The PCM looks at the 0/2 sensors for these changes. This problem is usually a faulty secondary air injection pump. The system should be tested before replacing the pump to confirm problem.


Secondary Air Injection Pump Replacement

  1. Raise the vehicle. Object Number:(NNN) NNN-NNNN Size: SH

  2. Disconnect both the air inlet and air outlet pipes from the secondary air injection (AIR) reaction pump.
  3. Remove the electrical relay from the AIR pump bracket.
  4. Disconnect the electrical connector from the AIR pump.
  5. Remove the 3 bolts securing the AIR pump bracket to the vehicle frame.
  6. Remove the AIR pump from the vehicle.

    Object Number:(NNN) NNN-NNNN Size: SH
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Customer: replied 5 years ago.

Additional information you may consider:


Water was found in the fresh air line leading to the air pump and frozen water found in the return line. The air pump had frozen water in it and would not activate. All water/ice was cleared from the pump. Is this an indication of a faulty air pump? Also, I will add that my mileage is only 71K. Would there possibly have been a defective air pump from the manufacturer since mileage is under 100K? Please advise...thanks.

Yes,this is an indication of a faulty air pump. I do not find a bulletin for this problem on this vehicle ,but I have seen it on others. The only thing I can tell you on this one is to your local GM dealer & have a face to face for assistance. You never know,they may offer to go they buy the part & you the labor.