DTAForum.com - a forum for the DTA ECU

Hi,
I'm planning to map AUX2 output based on water temperature, and use it to drive a bimetal temperature guage. However, when I connect the ECU and set up the AUX2 mapping with different duty cycles I see no change in the voltage (measured between +12v and AUX2). I did not have any load connected, just a digital voltmeter, but I was expecting to see the (averaged) voltage to change when the duty cycle was changed. The voltage is constantly ~10V, but if I use the test function and check AUX2 box, it changes to 12v.

Having read a few posts on similar topics here on the forum, it seems that the AUX(2) is only active when the engine is running. Is that so, and is there no way to have it active without the engine running? If not I can live with that, but what is the state of AUX2 when the engine is off? Is the signal floating, or why am I reading ~10V?

/Peter

You're seeing that value as there is no load connected.

There is no way to make AUX2 work without the engine running.

Ok, thanks for quick response!

And what about the state of AUX2 when the engine is off, can I be sure that my temp guage is not smoked? That is, AUX2 will never be grounded causing a high current through the load (guage) when the engine is not running right?

/Peter

When the engine is off, the ECU will hold the output at 12V.
When the engine is running, the ECU will switch the output at the frequency you have selected, and the duty cycle for that temperature.

You must check what the resistance of your gauge is, to ensure that the current draw isn't too high.

Thanks, all good then!

/Peter