MoTeC Global Forum

Apologies for the basic questions, new to wiring up a standalone ecu myself, so need to verify as i proceed.

I have removed the stock combination optical cam and crank position sensor on a Skyline RB26 engine and added a Marelli magnetic crank pickup sensor reading a 62 minus 1 tooth crank wheel, and a Bosch Hall effect cam sensor, reading a single camshaft wheel tooth. I want to use the stock Nissan engine loom as much as possible. I enclose a screenshot of the stock wiring up to the opti sensor connector. What I would like confirming is whether I can run the stock loom wires up to the plug, chop the plug off then split the ground and voltage leads to feed the two new sensors, and use the stock other 2 wires for the signal feeds to the ecu. It appears the 4 wires are encased in a common screen. Is this going to be OK done like that?

Bosch sensor data is at : http://www.mmcompsys.com/download_zone/ ... all_01.pdf

Stock wiring to stock opti sensor plug is in the image below, thanks.

Hello Chris,
The power wire to the original Nissan optical sensor is 12v and is connected to one of the main relays so you will not need to change this, it will supply power to the Hall sensor. Magnetic sensors do not need any power supply. You will be able to use the two signal wires from the original Nissan loom.

The ground wire can be split to both sensors without problem BUT you must remember that in Nissan looms the ground for the optical sensors is connected directly to a chassis earth and therefore cannot be connected to a 0v (B14, B15 or B16) pin on the MoTeC ECU, it should be connected to the Ground pin (A10 or A11).

Realistically we would recommend replacing the ground wire with a new wire connected to 0v on the ECU and not to chassis ground. From experience it can be difficult to find where the ground wire from the optical sensor is connected to the chassis as it can be connected in a few places. Replacing the wire altogether and connecting it to a 0v pin is the best thing to do.

Excellent info, this is a great forum, I feel as though I'm asking a lot of questions though, so thanks for your patience. The good thing is I am learning a great deal, so I am very pleased at its creation. Luckily I have kept the lid on my temptation to start wiring the ecu up until after the holidays, and you experts are back on line, so I can now get this part sorted with confidence. Thanks again! I'll add a separate wire to pin B16