Innovate Motorsports LM-2 - Manual (Page 40)

Document # 31-0008 LM2_Manual_1.3.doc 40
To connect the LM-2 to the EFI-computer, first determine what kind of narrow band
sensor is used, then follow the instructions below (you will need a digital multimeter to
determine correct OEM sensor wires):
a. Vehicle has a 1-wire sensor:
Wire analog output 1 directly to the wire.
b. Vehicle has a 2-wire sensor:
While the engine is off determine which of the 2 wires has a low resistance between the
wire and the sensor body. This is the heater power for the sensor. Wire analog output 1
directly to the other wire. Leave the heater power wire unconnected but make sure it
cannot ground itself.
c. Vehicle has a 3-wire sensor:
Typically the 3 wires are: heater power, Ground, and sensor element connection.
Generally they have 1 black wire and 2 white wires. Connect the black wire from the EFI
computer to analog output 1 of the meter. Leave the other wires unconnected but make
sure they cannot contact any metal parts or see above. If the wiring colors are different,
then heater power can simply be determined by measuring the voltage on the wires
when the engine is running. The wire showing 12V or more is the heater power. The
sensor element connection voltage fluctuates around 0.45V when the car is warmed up.
Wire analog output 1 directly to this wire. The Ground connection has low resistance to
chassis ground (less than 1 Ohm). Measure while the engine is off.
d. Vehicle has a 4-wire sensor
Typically the 4 wires are: heater power, heater ground, sensor ground, and sensor
element connection. Proceed as for the 3-wire sensor.