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 by-passes 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.