Begin by following the ‘Quick Start Guide’ that comes with the controller. If you lost that or need a copy of it for some reason you can download it here: LC-1 Quick Start Guide for the LC-1, LC-1/XD-1 Standalone Gauge Kit if you have the combo kit, or MTX-L Manual for the MTX-L.
In addition, DIYAutoTune recommends:
- Grounding the controller and the MegaSquirt together. This is to prevent a voltage differential and will ensure accurate readings.
- The factory EFI system’s fuel pump relay often makes a good source for 12v switched power. This is a required source for 12v, but often a good one…
- For the LC-1, wire the brown (analog out 2) wire to the MegaSquirt’s O2 input wire. For the MTX-L and LC-2, the default analog outputs are reversed, so you’d wire the yellow (analog out 1) wire to the MegaSquirt’s O2 input wire.
For any LC-1 purchased after June2006, that should be all you need to be concerned with when wiring it up.
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IF YOU PURCHASED YOUR LC-1 PRIOR TO JULY, 2006: Use a 470 ohm, 1/4watt resistor in between the analog output of the LC-1, and the o2 input of the MegaSquirt. So you’ll wire the analog output from the LC-1 to one side of the resistor, and then you’ll wire the MegaSquirt 02 input to the other side of the resistor, forcing the signal to pass through it.