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. Conversely, if the temperature in the resistor of the sensor rises, the current drops gradually.
DTC P0135 is a pending code. The root cause will be confirmed by P0030, P0606, P2243, P2251.
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 | Case1 |
•
Heater PWM > 1.56%
•
Sensor operative readiness (Tip temp.>640°C(1,184℉) or 18sec. heating time after Dew-point detection) | |
Case2 |
•
11 ≤ Battery voltage ≤ 16V | ||
Threshold Value | Case1 |
•
Front HO2S tip temp. : < 755°C(1,391℉) or > 900°C(1,652℉) | |
Case2 |
•
Error bit information from HW circuit | ||
Diagnostic Time | Case1 |
•
Temp. < 640°C(1,184℉) : 1sec.
•
640°C(1,184℉) < Temp. < 755°C(1,391℉) : 10sec.
•
900°C(1,652℉) < Temp. : 10sec. | |
Case2 |
•
5 seconds | ||
MIL On Condition |
•
2 Drive Cycles | ||
HO2S Heater | Normal Parameter |
18 ~ 20℃ | |
Heater Resistance | 2.4 ~ 2.9Ω |
