P0031

DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)

1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of heater. The heater performs duty control, and the output terminal voltage at ON is 0 V and the output terminal voltage at OFF is the battery voltage. Judge as NG when the terminal voltage remains Low.




2. COMPONENT DESCRIPTION




3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.

5. DIAGNOSTIC METHOD




Abnormality Judgment
Judge as NG when the continuous time of completing the malfunction criteria below becomes more than 1 second (8 cycles).




Normality Judgment
Judge as OK and clear the NG when the malfunction criteria below are completed.

6. DTC CLEAR CONDITION
- When the OK idling cycle is completed 40 times in a row
- When "clear Memory" is performed

7. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle is completed 3 times in a row
- When "clear Memory" is performed

8. FAIL SAFE
- Front oxygen (A/F) sensor heater control: Not allowed to turn on the heater.
- A/F main learning: Not allowed to calculate the A/F main learning compensation factor.
- A/F sub learning: Not allowed to calculate the A/F sub learning compensation factor.
- Purge control: Not allowed to purge.

9. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)