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LSU 4.9 Wiring

Practical Motorsport Wiring - Professional Level

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I have a project coming up soon that will have two LSU 4.9's. I was wondering how everyone wires them up. Do you use 6 indivdual wires for each sensor in the harness? I was thinking of using some 6 conductor shielded twisted pair cable that ProWire sells. Would that work? Should I ground the braid to Batt- or sensor ground? Thanks!

No need to shield them. If you're looking for the best accurate signal possible, get a wideband controller that communicates via CAN. Depending on the device controlling them, I usually wire them up separately.

Thanks. I'll be using a MaxxECU Pro which has two dedicated O2 interfaces. Really I was just going to use the 6 wire cable for convenience, but didn't know if that was the best way to do it.

Where did you get 5 wires from? Most LSU4.9 controllers will need 6 wires. I think only innovate doesn't use the calibration resistor on the 6th pin and therefore only need 5 wires. You can use a jacketed cable if you wish but since you are posting in the professional motorsport category I would say most in this application would use individual wires as they will have stock of good motorsport level single conductor wire in stock, but not many would keep 6 core tefzel in stock. Also if weight or bundle size is a consideration by using individual wires you can use say 22AWG for only the 2 heater wires and something smaller for all the low current wires.

Hi Adam. Thanks for the reply. The 5 wires in my original post was a typo I edited it.

I mostly consider using it for convenience sake as it isn't very expensive on ProWire's site.

Thanks for the help!

CANbus controller adds some amount delay/lag in the O2 reading. Some ECU's have a table you can configure that, so it can make smarter corrections.

You can also improve sensor accuracy by twisting the Pump wire with the Resistor and the Nernst Cell with the Ground. Those are differential signals, so twisting improves accuracy and reduces noise in the raw signal.

sorry to open up an old thread. I just have one follow up question. Is it safe to run 22 AWG tefzel wire for the 12V heater wire for the bosch LSU 4.9? and should the sensor be fused? if so, what size fuse?

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