MoTeC Global Forum

How do you test the motec wide band sensor on the m4? This is on a jest ski and I have four of them and can not get any change from on the lap top when live. The heater is on and all sensors get hot. The Black wire is on pin 31 and the grey is on 32.They may have water damage.
Dale

There is no "test" for lambda sensors.

First of all are you sure they are wide band sensor? Some narrow band sensors have 4 wires.
I cant remember which is the + la input on the ECU but the Black wire is + and the gray is - on the sensor.

If you have access to the Tune, make sure the M4 has the wideband optipn enabled.
If it is enabled the go to sensor setup and make sure the lambda input is set to wideband.

To start reading lambda, the ECU must see a rich then lean fuel value, sometimes this does not happen so manually bump up the fuel once the engine has warmed up.

One thing to note about the 4 wire sensor is they can read incorrectly due to contamination so even if they display something they may not be correct. If you have not used leaded fuels or additives then this is not a issue.

You could manually check the output of the sensor with a voltmeter you should see less than 1V once it has warmed up