Confirming wiring for LC1 using Megasquirt in an M30B35

[cvillebimmer]

Working on getting this car back on the road. The LC1 has been wired into the O2 plug as follows. Is this a reasonable way to go? Or are there better alternatives?

O2 plug wire_____________LC1 wire
Black(2)--------------------------->Brown / analog out 2
White(4)--------------------------->Red / 12V supply
White(3)--------------------------->(not connected)
Grey(1)---------------------------->Blue + Black + White / all grounds

It struck me as odd that only one of the white sensor heater wires was connected.

Thanks in advance!

[T_C_D]

blue and white - chassis ground
red - switched 12v
brown - signal to MS
yellow - signal to optional gauge
black - not used

[cvillebimmer]

Sorry for the barrage of questions, electrics is not my forte.

Innovate's instructions below, and others here, recommend using the same ground as MS. This would lead me to believe I should use the ground wire in the O2 harness, not the chassis ground. Am I misunderstanding?

Any harm in using the switched 12v from the O2 harness?

5. The BLUE and WHITE wires should all be grounded to the same ground source. Optimally, these (and any other MTS device ground) will be soldered to the same lug, and connected to a single point. When this isn’t possible, connect each one to a separate lug, and attach in close proximity. Multiple lugs on the same bolt is not optimal, and can result in unwanted signal “noise.” When possible, soldering is always better than crimping.

[9mil]

What did you end up doing and did it work?

Brown wire to MS and chassis ground?

Thanks!

[cvillebimmer]

The LC-1 is working fine now. It was fried, and needed to be replaced.

In addition to replacing the sensor, I also sourced switched power from the auxiliary fuse box instead of the O2 sensor wiring harness.

Haven't done anything else as I also confirmed an HG leak. The cooling system will consistently over-pressurize after a quick boosted run. Not sure yet how/if I'm going to proceed.

[9mil]

So it was working as the o2 input for the MS - correct.... I am going to scrap the stock o2 and just use the brown wire from the lc1...

Thanks!

[cvillebimmer]

So it was working as the o2 input for the MS - correct.... I am going to scrap the stock o2 and just use the brown wire from the lc1...

Thanks!

Yes, that's right. The only O2 sensor I'm running is the LC1

[9mil]

Are you using an adapter board for a 179 motronic harness by chance?

[cvillebimmer]

Honestly, not sure.

I'm running a plug and play box from Peter Florance.

[9mil]

Gotcha- I'm rigging all this up with a 179 harness in a pre- motronic e24 and am debating what to do with the IAT sensor wiring.
Guess ill jump in after the goathumper moronic adapter board, before the MS unit- in the relay cabling.... Same with the O2 wire.

Thanks for the info!