How to Check the Code P0031 H02s Sensor.

How to Check the Code P0031 H02s Sensor.

 

How to Check the Code P0031 H02s Sensor.

Model: Hyundai Genesis (EQUUS) VI

Year of Model: 2009 and Above

Fuel: Gasoline

Displacement: 4600cc

 

2011  G 4.6 DOHC  Engine  Engine Control  P0031 HO2S Heater Control Circuit Low (Bank 1 / Sensor 1)

Study Guide and Component Location Study Guide and General Description Study The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850°C(662 to 1562°F). Study The HO2S heater greatly decreases the amount of time required for fuel control to become active. Study The ECM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. Study On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually. Study Guide and DTC Description Study If the sensor output is below 0.06 V under enable conditions, ECM sets DTC P0131. ( This DTC might be caused by the malfunction of Heater circuit, so, check the heater circuit first. ) Study Guide and DTC Detecting Condition Item Detecting Condition Possible Cause DTC Strategy Study • Power stage diagnosis • Poor connection • Short to ground in control circuit • B1S1 Enable Conditions Study • - Threshold value Study • Short to ground Diagnosis Time Study • Continuous MIL On Condition Study • 2 driving cycle Study Guide and Specification Heater Resistance (Ω) 8.1 ~ 11.1 Ω at 21°C(69.8°F)  Study Guide and Signal Waveform & Data Study Guide The signal waveforms of front HO2S(the lower) and heater(the upper) at idle Study The output voltage of front HO2S is changed continuously accroding to air/fuel ratio, ECM controls fuel amount based on this value. Preheating is necessary for HO2S normal operation. Study Therefore heater unit is installed in HO2S, ECM can control air/fuel ratio with the output signal of HO2S simultaneous with engine run by reducing preheating time. Study ECM controls heater with duty cycle. Study HO2S' power source is main relay and ECM operates heater by ground control.