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Lotus Service Notes
Section EMP Page 15 O2 Sensor (Pre Catalyst) P0131 P0132 P0133 P0134 P0135 P0131 O2 Sensor 1 Circuit Low Voltage P0132 O2 Sensor 1 Circuit High Voltage P0133 O2 Sensor 1 Circuit Slow Response P0134 O2 Sensor 1 Circuit No Activity Detected P0135 O2 Sensor 1 Heater Circuit Description The oxygen sensor monitors the oxygen content in the exhaust gases. The sensor consists of a zirconia elec- trode between two platinum plates. When zirconia comes into contact with oxygen, it becomes an electrical conductor. The exhaust gases pass through louvers in the sensor. One plate is in contact with the outside air and the other plate is in contact with the exhaust gases. The platinum plate in contact with the air is electrically negative due to the oxygen in the atmosphere and the plate in contact with the exhaust gases is electrically positive. This will cause a difference in electrical potential to develop between the two plates. Thus the voltage across the platinum plates ranges approximately from 100 millivolts to 900 millivolts, depending on the oxygen content of the exhaust gases. Thus when the air/fuel mixture is rich, the oxygen sensor output will be high. If the air/fuel mixture is lean, the oxygen sensor output will be low. Sensor connections Sensor Connector Description ECU Pin ECU Connector 1 Signal 15 (A3) 52 Way (Left) 2 Ground 41 (F4) 52 Way (Left) '06 M.Y. in brackets 3 Heater 1 (K3) 52 Way (Left) 4 Battery Voltage - - Sensor characteristics Normal operating range is 0 – 1000mV Malfunction Criteria P0131 Set when the sensor operates below 5mV for more than 1.5 seconds consecutively for a specified number of times. Monitor: Continuous Disable Criteria: DFCO (Deceleration Fuel Cut Off) Potential failure modes: • Low fuel pressure (Lean mixture) • Malfunctioning sensor • External water on sensor • Sensor wire shorted to ground P0132 Set when the sensor operates above 1200mV for more than 1.5 seconds consecutively for a specified number of times. Monitor: Continuous |