What Does Resetting An Ecu Actually Do?

[chrisR34GTT]

Ok so i am still having problems with my boost controller but rather than trying to describe the problems I am having I thought I would describe how I am making it work (temporarily that is).

The unit is a hdi evolution d with electronic boost gauge and car is an R34 manual coupe. Now if I reset the ecu (disconnect negative battery terminal and switch headlights on for a few minutes, turn them off and hook it up again) the boost controller will work fine when I drive it, but once I turn the car off and leave for a long period of time, say overnight, it won't work the next time I start the car up and I have to reset the ecu again...

Now my question is, what is occuring when you reset an ecu and moreover what in particular could this be doing to the boost controller?

Honestly the car drives great when the unit is working but it is becoming an absolute pain the rear to have to continuously reset the ecu that I am tempted to just get a different unit.

[R34_Wong]

Sure its the ECU?

Unplugging the battery would also be terminating power to your Boost controller... maybe you've got a faulty boost controller unit?

Why do you say its failing to work? As it's an electrical boost gauge, does the metre the stock boost levels or...?

[chrisR34GTT]

I wasn't actually alluding to the ecu being the problem, merely that reseting it gets the unit up and running again...

Ok, so the terminating of the power to the boost controller what could that be doing, I have a feeling that my ignition earth (if thats what is called) is not working and that might be causing the problems. So therefore the method of reseting the ecu, by draining the remaining charge/current it is able to function again.

And I am not sure what you mean "by does the metre the stock boost levels or..?" If you mean am I running stock boost, no I'm running about 10-11psi.

Lastly, the unit isn't faulty as I sent it back to HDi for analysis and sent it back claiming it is 100% operational...

If disconnecting the battery fixes the issue, then the problem is purely electrical right? That leaves the wiring and solenoid?

[mosquitocoils]

Ok, so the terminating of the power to the boost controller what could that be doing, I have a feeling that my ignition earth (if thats what is called) is not working and that might be causing the problems.

If disconnecting the battery fixes the issue, then the problem is purely electrical right? That leaves the wiring and solenoid?

I think you just figured out what to do next

[R34_Wong]

I was refering to the boost gauge as you mentioned it was a problem with the boost controller (which we still don't know what the problem is other than its faulty...).

So what I thought was that if its faulty it probably means its not holding the boost level you want or not dialling it up to the amount you want (which you a probably verifying by looking at the boost gauge).

But anyway, looks like you potentially have an idea and I hope it works out.

Good luck mate.

[chrisR34GTT]

The problem is too hard to describe and I didn't want to confuse people, working back from the fact that disconnecting the battery sort of resets the boost controller seemed like a logical direction? Sorry for the confusion though mate.

Ok so I checked the wiring and it is all perfect (wires match up to installation guide, soldering appears solid). Now I have no experience with electronics so could someone explain to me how I you check the car is earthing correctly. I take it I will need a multimeter? And make it real simple like for me if you could lol

And if that turns out to in working order how would I check to see if the a/m solenoid is working correctly?

Thanks!