Test Description

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

1. 3
   
   This step isolates the condition. If all DTCs are set, this indicates that one of the heater low circuits are grounded. An internal HO2S condition can also cause all DTCs to set.
2. 4
   
   This step determines if the bank 1 sensor 1 heater high circuit is shorted to a ground.
3. 8
   
   The bank 1 sensor 1 and the bank 2 sensor 1 are internally connected within the PCM. If the voltage measurement is within the specified range, the bank 2 sensor 1 is causing the condition.