Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 2
   
   Other secondary air injection DTCs should be diagnosed first if set. If the HO2S voltage remains below 50 mV for approximately 5 seconds, the system is operating normally.
2. 4
   
   Listen for a running motor. Command both the ON and OFF states. Repeat the commands as necessary.
3. 5
   
   Listen for a click when the device operates. Command both ON and OFF states. Repeat the commands as necessary.
4. 6
   
   This step begins to eliminate an airflow problem.
5. 9
   
   This step tests for a vacuum leak at the valve.
6. 10
   
   This step tests the operation of the valve.
7. 12
   
   This step tests the control circuit for operation.
8. 13
   
   This step bypasses the relay to test pump operation.
9. 15
   
   This step tests the control circuit for operation.
10. 18
    
    This step eliminates the relay and the control circuit as a cause for continuous pump operation.
11. 19
    
    This step tests the control circuit for operation.
12. 40
    
    The pump may have failed from another fault. If the pump operates without a command, refer to step  18.
13. 42
    
    If the HO2S voltage remains below 50 mV for approximately 5 seconds, the system is operating normally.