Scottish Elises

Can anyone tell me what pin out on the rover MEMs triggers the tacho?



Cheers


Mac

I think its pin 12, going on the assumption that an emerald is MEMS pin compatable.... It should be a pulsed 12v signal, so you'll need a multimeter that can measure frequency to diagnose....

Still goosed then

http://www.mgfcar.de/schedules/sb9.jpg

Link is to a schematic of the non-VVC MEMS. Doesn't appear to identify pin no.s but gives wire colours. Tacho is white with black tracer.

If it's VVC it's pin 9 per link below

http://homepage.swissonline.ch/TomsSeve ... %20RED.htm

111Robin wrote:http://www.mgfcar.de/schedules/sb9.jpg

Link is to a schematic of the non-VVC MEMS. Doesn't appear to identify pin no.s but gives wire colours. Tacho is white with black tracer.

If it's VVC it's pin 9 per link below

http://homepage.swissonline.ch/TomsSeve ... %20RED.htm

Looking at the circuit diagram, the tacho drive is identified by C159-12. You'd read that as connector 159, pin 12

I thought all EU2 MEMS plugs were the same, as an emerald ECU is plug'n'play for these cars.... The pinouts seem to be "completely different" on those two diagrams...

Anyway.... Mac, as you dont have VVC, you need to look at the wiring coming from pin 12 to the tacho

First schematic is correct then, showing pin 12 for non-VVC. Second link is for the VVC, pin 9, white wire/black tracer on both.

Aah, i see... there are 2 versions of mems used... Mems 1.9 and Mems 2. This explains it

Pin 12 would be where?

Which end do I start counting from ??

Mac,

if it's on the Caterham just look for the white + black wire on the smaller of the 2 ECU plugs. ( or maybe ask Mandy to look )
Should connect to pin 2 of the grey (engine loom to chassis loom) multi plug situated about halfway along the O/S top chassis rail.

Kayfur wrote:Mac,

if it's on the Caterham just look for the white + black wire on the smaller of the 2 ECU plugs. ( or maybe ask Mandy to look )
Should connect to pin 2 of the grey (engine loom to chassis loom) multi plug situated about halfway along the O/S top chassis rail.

I'm EU2 so only have one ECU plug.

With Black & White being shades then I should just about manage


Mac

Looking on the pin side of the connector it will be on the bottom row, first on the left (ref. the second link that shows the opposite side of the VVC connector with the pin numbers identified (note it is pin 9 on the VVC, not 12 as per non-VVC).

Clear as mud ?

Don't have the EU2 engine loom diagram but the tacho should still connect via the WB wire to the grey ( coffee coloured ? ) multi plug so you can trace back if the ECU pin numbering advice is confusing.

Kayfur wrote:Don't have the EU2 engine loom diagram but the tacho should still connect via the WB wire to the grey ( coffee coloured ? ) multi plug so you can trace back if the ECU pin numbering advice is confusing.

Apparently the coffee I drink is actually Lime Green in colour

http://homepage.swissonline.ch/TomsSeve ... _Logic.htm

Info on how to test the circuit

Lawrence has the pin-out on his site:
http://www.hoymotorsport.pwp.blueyonder ... r_m3dk.htm

From that pin 12 is right and you can see in the diagram where it is.

Pin 12 works a treat.

The existing set up use an inductive loop on the king lead and a split the LT side of the coil. - Now sorted to run off the ecu output