Lotus 2004 Eleven Service Notes page 158

Lotus Service Notes
O2 Sensor (Pre Catalyst)
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
1
2
3
4
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
P0131
P0132
P0133
P0134
P0135
Description ECU Pin
Signal 15 (A3)
Ground 41 (F4)
Heater 1 (K3)
Battery Voltage -
ECU Connector
52 Way (Left)
52 Way (Left)
52 Way (Left)
-
Section EMP
'06 M.Y. in brackets
Page 15