P0052 (U5/Low Emissions)

DTC P0052 - HO2S HEATER CONTROL CIRCUIT HIGH (BANK 2 SENSOR 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 High.




COMPONENT DESCRIPTION




ENABLE CONDITION

GENERAL DRIVING CYCLE
Always perform diagnosis continuously.

DIAGNOSTIC METHOD




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




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

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

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

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.
- Compensation when starting the engine at high temperature: Make the MIN value to be 0 from 0.06 normally.
- Purge control: Not allowed to purge.

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