LC-1 ground question

[Dan D]

I have an LC-1 WBO2 I'm installing with the DB gauge. In addition to that, I'm running it into the EGR input to log via pocketlogger.

The instructions from Innovate state conflicting information:

Gauge Instr:

Connect the gauge’s BLACK ground wire at the LC-1’s
White ground point. This ground point should ideally be an
engine block ground.

Part 1 of LC-1 instruction:

The BLUE (heater)and WHITE (system)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.

Part 2 of LC-1 instructions:

If an external data logger or ECU is to be fed by
an MTS device, the MTS ground should be located at or near the ECU or data logger’s input
signal ground. If one analog output of the LC-1 is used to drive an AFR
display and the other output is used to connect to an ECU, the AFR display ground should be
connected to the ECU ground.

Based on that I have two options:

1. Use ground wires I ran into the cabin form the intake manifold ground for all ground locations so they meet the criteria in the first two instcutions. If I do this, the ECU has a different ground than the LC-1 & Gauge.

2. Use the ECU ground wire (right next to the ECU) for the gauge and LC-1 system ground and the wire to the intake manifold as the heater ground

(3./4. Disconnect the ECU ground and run a new ground wire to the same point the on the intake mani. I don't like that idea because I'm sure Mitsu had something in mind when they chose ground locations. Or ground everything at the ECU, which I also don't like because I don't think the heater wire ground should share that point.)


I'm a EE and I see this is as one of those situations where practice beats theory. I'm leaning toward #2. Has anyone with an LC-1 installed one of these ways and had good success where the logger, gauge, and maybe even an external reference matched well.

 

[Boostdtalon]

Ok I just reinstalled my LC-1 with DB gauge last night. I soldered the blue and white wire together with a ring terminal and grounded it to the chassis. We tooled with it for a while to make sure it worked properly and it did.

 

[Dan D]

Are you logging through the ECU as well?

 

[Boostdtalon]

No I'm not.

 

[mooserage]

Ok, just to reply to this because I had to work with mine the other day. I wired everything, gauge and lc1 grounds to the ecu's ground point in the cabin. There is a picture in the instructions somewhere that have a picture showing this and its also the easiest way. Its been about 6 months and I've never had a problem. I am also using the lc1 as my primary o2 sensor to my AEM, so its very important it works haha.
-shamus

As a note: This is heater, gauge, lc1 grounds all on a ring terminal together.

 

[Dan D]

The picture in the manual shows the common ground point, but recomends it be an engine grounding point vs chassis (like our ECU)so I was uncertain if the ECU ground location would work well. Sounds like you've had success so far. That's good to know.

 

[mooserage]

Yeah I had the same exact confusion at first, but with the recommendation of a reputable tuner and that picture, I just went for it /ubbthreads/images/graemlins/smile.gif Good luck!
-shamus