Skip to main content

Wideband O2 monitor

The electric power steering pump (EPS) draws high currents, so if the ignition is left on the battery is quickly drained. I've also installed an LC-2 wideband controller, which should not powered/heated without the engine running

LC-2 manual:

Do not pre-warm the sensor before starting the engine, simply start the engine as normal. Allowing the sensor to pre-warm before starting the engine will increase the possibility of damaging the sensor from shockcooling. 

I came up with the idea of using a voltage monitor, so that the LC-2 and the EPS only receives power when the starter battery is charging - indicating that the engine is running. The voltage monitor has two configurable set-points, a start voltage and a cut-off voltage.

The voltage monitor controls a relay supplying the LC-2 and the EPS directly from the starter battery, as recommended by Innovate.


I mounted all the hardware on an acrylic plate that I fixed to the back wall of the glove box. This provides easy access, as well as hiding the clutter away from view. A flyback diode is added to the relay to counter the EMF generated during coil de-energization.