The linear O2 sensor is mounted on the front side of the Catalytic Converter (warm-up catalytic converter) or in the front exhaust pipe. It detects a wide range of air/fuel ratios in the exhaust gas from the rich to lean regions. This linear O2 sensor produces a current that corresponds to a specific air/fuel ratio. The PCM monitors this signal and determines whether the air/fuel mixture is rich or lean. The PCM constantly monitors the linear O2 sensor and increases or decreases the fuel injection duration using this signal. This is called closed-loop fuel control operation.
The PCM monitors front O2 sensor pumping current circuit(VIP) and sets DTC P2237 if front O2 sensor signal stuck is detected.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
Electrical check - check symptoms related to Lambda sensor open circuit | 1. Poor connection or damaged harness 2. Open in HO2S control circuit 3. Front HO2S |
Enable Conditions |
•
Wide range sensor pump current valid | |
Threshold value |
•
Pumping current circuit open (VIP)
•
Signal < 2.1V during fuel cut off | |
Diagnosis Time |
•
Within 15 sec. after related symptom detected. | |
MIL On Condition |
•
2 driving cycle |
