The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850℃(662 to 1562℉). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The PCM 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. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.
The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850℃(662 to 1562℉). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The PCM 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. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.
The PCM determines if a front HO2S heater fault has occurred and sets DTC P0030 if the front HO2S heater control driver inside the PCM fails, if HO2S is not operational (after an elapse of predetermined time) since engine start, or when the front HO2S tip temperature is out of normal working range.
The PCM determines if a front HO2S heater fault has occurred and sets DTC P0030 if the front HO2S heater control driver inside the PCM fails, if HO2S is not operational (after an elapse of predetermined time) since engine start, or when the front HO2S tip temperature is out of normal working range.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Evaluate O2 sensor Element Temperature via measuring Element Resistance | 1. Related fuse blown or missing 2. Heater control circuit open or short 3. Power supply circuit open or short 4. Contact resistance in connectors 5. Faulty HO2S |
Enable Conditions |
•
O2 sensor pre-heating phase finished (dew point passed)
•
No relevant failure
•
Coolant temperature drop since the last engine stop > 25℃(77℉)
•
10V< Battery voltage <16V
•
3.5%< O2 sensor heater control duty < 96.5%
•
O2 sensor operative ready (to ensure no open circuit failure present) | |
Threshold Value |
•
HO2S internal resistance > 2500Ω~9500Ω | |
Diagnostic Time |
•
90 sec. | |
Mil On Condition |
•
2 Driving Cycles |
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Evaluate O2 sensor heater performance | 1. Related fuse blown or missing 2. Heater control circuit open or short 3. Power supply circuit open or short 4. Poor connection or damaged harness 5. Faulty HO2S |
Enable Conditions |
•
No relevant failure
•
11 ≤ Battery voltage ≤ 16V
•
Sensor operative readiness (Tip temp. > 640°C(1,184℉) or 18sec. heating time after Dew-point detection)
•
Heater PWM > 1.56% | |
Threshold Value |
•
Front HO2S tip temp. : < 755°C(1,391℉) or > 900°C(1,652℉) | |
Diagnostic Time |
•
Temp. < 640°C(1,184℉) : 1sec.
•
640°C(1,184℉) < Temp. < 755°C(1,391℉) : 10sec.
•
900°C(1,652℉) < Temp. : 10sec. | |
Mil On Condition |
•
2 Driving Cycles |
Temp.(℃) | Temp.(℉) | Heater Resistance (Ω) |
18 ~ 20 | 64 ~ 82 | 3.3 ~ 4.1 |
HO2S Heater | Normal Parameter |
18 ~ 20℃ | |
Heater Resistance | 3.2±0.8 Ω |
BINARY
LINEAR
