DTAForum.com - a forum for the DTA ECU

Hi guys,
I'm building a kit car using an E48 ecu, and have installed all my dash gauges, the rpm counter is wired up but the tacho out pulses per rev is set to 0. It says it can be a value between 1 and 6, I'm trying to set it to 2 but everything I change it it reverts to 0. I can change other values on the general engine settings tab, just not this one (unfortunately it's the only one that's wrong).
Any help would be appreciated,
Thanks,
Alex

You might have a very old firmware that wont allow this to be changed ?

It was a feature Allan added after I requested it way back when I had the P8, must be a good 13 years ago. Although pretty sure it was just a software change for that.

Alex might know better.

Hmm.. Could be, how do I go about updating the firmware?

Before my time I'm afraid.

To flash the E48, you need to pull the chip and flash it with a flasher. The firmware is in the downloads section of the website.

do you need to change it at all or is it reading wrong? i.e. if 4 cylinder engine it will output 2 pulses per rev prior to the software changes.

It just isn't outputting anything, and I have nowhere else to take a signal from, spoke to Southam racing and they said the tacho out function has never worked on the E48 ecu... So a bit stuck for ideas now.

Garstly wrote:It just isn't outputting anything, and I have nowhere else to take a signal from, spoke to Southam racing and they said the tacho out function has never worked on the E48 ecu... So a bit stuck for ideas now.

I would find that rather hard to believe.

Unless your ecu happened to be faulty. And how are you determining it isnt outputting anything, what tests have you done ?

And what type of ignition coil, are you using ? You could probably just hook the tacho up to a coil trigger like an old style system.

I'm pretty certain it's not giving a signal, have had two gauges wired up to it, and neither worked. Also the ecu is set to a 0 value for that so you wouldn't expect it to be giving an output.
I did try running off the coil, didn't get anywhere with it but that's not to say I was doing it right, how would i go about wiring that up correctly? I'm running a standard twin coil system

So you havent actually tested for a signal ?

Tacho's for many years simply took their signal from the trigger wire on the coil. The DTA would have 1 if you are retaining a dizzy or 2 for a wasted spark.

So you could use either of these, but output 1 probably makes most sense.

Exactly what tacho is it you have, and are you sure it works ?

It is a vdo tacho that has been tested on another car, I tried using the trigger and that didn't seem to work either