question re Instrument Cluster - Help! (Ron, Andy, Jon, anyone)!

I was looking on the ETK online (it was $20 for one day), and was looking at the connectors to the instrument cluster...


I need to figure out which input drives the electronic signal to the tachometer.

I think the speed signal is on X271 pin 4 for the speedo, but where is the RPM lead?

Any ideas where I could tap into an RPM lead?

I could not figure out on figure 6211.0-05 schematic just how the tach works......

any ideas???

help!!!

To recap, which lead would give the speed, and which the tach/engine RPM??

Thanks in advance for any and all help!

X17-2 = speed out

EWS module X1805-5 black = TD (tach)
See pic. Pin 5 is two over to the right of pin 7

EWS module is under the dash on the drivers side up and to the left of the steering column.

It was a learning experience!!!

I really appreciate (and admire!) your expertise and familiarity with these machines!!

I will repay at the next homecoming!!!

Thanks, Ron!

A heads-up display with tachometer, speedometer, and other functions available..........


Nifty little gadget!

made by:

DEFI

sold by:

http://www.ilpperformance.com/defihud.html

or

http://www.spipowerexcel.com/

is it equivalent to the pin on the instrument display?

the idea would be to pick off the ignition, power, ground, dimmer, speed/GAL off the radio harness and then find the other connector without disassembling the speedo/tach instrument cluster....

is it feasible?

Originally posted by hdd3md
is it equivalent to the pin on the instrument display?
is it feasible?

Yes. Comes from the same point.

thank-you!

whoa, that Defi stuff is sweeeet.

Argh...if only it's that simple on the E46 cluster...

For the longest time, I have been trying to figure out which is the tach signal even with the printout of the wirings. It seems that the tach signal is running into the CAN Bus, which now makes it quite difficult to tap.

Unless of course, tapping it out of the ECU box...

Originally posted by Ron Stygar
X17-2 = speed out

EWS module X1805-5 black = TD (tach)
See pic. Pin 5 is two over to the right of pin 7

Originally posted by VinceTopasBlau3
Argh...if only it's that simple on the E46 cluster...

For the longest time, I have been trying to figure out which is the tach signal even with the printout of the wirings. It seems that the tach signal is running into the CAN Bus, which now makes it quite difficult to tap.

The 01 and later Z3-M 's use the CAN bus too (see pics).
I assume that yours would be similar. What wiring diagrams are you using (Bentley)?

Ron,

Thanks for the heads up.

I got my print out from a mechanic at the dealer. The Bentley isn't very helpful with this. The printout details the signal type and measuring note of the two connectors on the E46 cluster, one with 26 pins and the other with 18 pins. There are two pins dedicated to CAN bus high and Can bus low and I am suspecting the tach signal has to run in one of them. And there is absolutely no single pin responsible for the tach signal.

I think a mux/demux is involved here. What do you think?