Could a MPGuino / SuperMID cause ECU issues if installed wrong ?

[Cd]

I recently fixed ( knock on wood ) an issue with my ECU on my 1993 Honda Civic DX.

I am now going to reinstall my SuperMID ( basically the same as a MPGuino ) and i had forgotten how that the wiring went.

I looked up Bens' helpful write up here :
crxMPG – Gas mileage never looked so good » SuperMID: Fuel Economy Display

on how to wire the SuperMID to the car and noticed a mention of the ECU.

My question is this :


If i somehow wire up the SuperMID wrong*, or do some bonehead move, is there a chance that i may short out my ECU ?

* meaning all the correct wires in the correct places, but with something causing a short in the wires.

BTW, My usual way of using the SuperMID has been to hit the reset button at the back of the SuperMID each trip that I take and to unplug the data cable from the SuperMID each time that i turn off the car - otherwise the SuperMID stays on and i would think it might drain on the battery.
Also, *this allows me to store the SuperMID in the glove box away from the scorching Texas heat and thieves who might think it is something that it is not.

I emailed Yoshi long ago, and he stated that i shouldn't have to unplug the SuperMID or hit the reset button each time that i use the SuperMID.

Since I had a habit of doing this anyways ( see the reasons above* ) could this have caused my ECU to develop problems ?

Should i install an inline fuse somewhere in the power line to the SuperMID or some other protective feature ?

Thanks !

[Cd]

Another funny thing that was happening with the car was that the VehicleSpeedSensor was giving erratic results and finally quit all together.
I purchased a new VSS and it still gave erratic results.

After plugging in the ( ebay used ) ECU, the VSS seems to have fixed itself.

Since the SuperMID also is wired into the VSS, and it went bad, this has me wondering if I shorted something somewhere.

[cbaber]

It all depends on your wiring. If you tap into the VSS and injector leads properly, meaning good connections and insulation, you won't have problems. The ports on the supermid or mpguino are simply inputs, they should never send out voltage if that's what you are thinking.

You need to be careful where you tap into power. I took mine off the radio harness because its constant 12v and is on a fuse. It also does not affect anything but radio if I shorted something and blew the fuse.

You should not unplug your device and reset it after every trip. These devices use little power. They won't drain the battery. Plus, you lose important tank data.

[Cd]

Cbaber, where did you hook into the VSS ?
I'm not finding where I connected it last time I had it working.

[cbaber]

This should help you a lot:
.:FFS TechNet : OBD1 ECU Pin out Schematics :.

Just find the VSS pin and cut the wire about 2 or 3 inches from the connector and then solder your wire into it. Same thing for the injector lead.

[Cd]

Sorry to make you go through all the trouble of posting that, but I already know where my VSS is ( in fact I replaced it because it seemed to be faulty.
I was just wondering if there was some other area that is better than splicing right into the wire.

[NachtRitter]

Cd -

I ended up opening the ecu harness connector (there are plastic clips on the harness connector which you can unclip) and the slipped my mpguino vss wire in with the car's vss wire. I think I have a writeup with pics here somewhere. Unfortunately not at my computer at the moment, so I can't search.

[Cd]

Hey don't worry. Thank you for the time you took to post though.

I'm hesitant to go anywhere near my ECU because I just replaced it.

[NachtRitter]

Ah, here it is: http://ecomodder.com/forum/191516-post13.html