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 conducts the duty control. The output terminal voltage at ON becomes 0 V, and the output terminal voltage at OFF becomes battery voltage. Judge NG when the terminal voltage remains to be Low.




2. COMPONENT DESCRIPTION




3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE
Always perform diagnosis continuously.

5. DIAGNOSTIC METHOD




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




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

4. DTC CLEAR CONDITION
- When the OK idling cycle was completed 40 times in a row
- When "Clear Memory" was performed

4. MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle was completed 3 times in a row
- When "Clear Memory" was performed

4. 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.

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