ECU ground or chassis ground?? Calling all electrical whiz-kids!!

[MrBoost]

I had to take my AVC-R out of the car to troubleshoot a problem, and need to wire everything back now.

My questions are, (please see attached pic),

1) Would there be a problem with tying the 2 grounds together and putting that to a chassis ground INSTEAD of tying it to the ECU ground??

2) Why the heck are there 2 ground wires in the first place? What sort of a difference (voltage? potential?) is the AVC-R looking for?

3) Does the AVC-R draw to much current for pin 92 (ground) of the ECU?

I had it hooked up according to the pic before, and everything *seemed* to be working fine, but I ended up shorting out the sensor ground track on my ECU, but I only had the AVC-R and (before DSMLink) the AFC hooked up to the ecu ground (pin 92). I obviously dont want to short out the ground track again....



What do you guys think?

[redturbo66]

It doesn't matter which ground is used. Grounds are common. They all tie in together. The reason there is more than one is because making more grounding points makes electricity more stable.

[MrBoost]

Originally Posted by redturbo66

It doesn't matter which ground is used. Grounds are common. They all tie in together. The reason there is more than one is because making more grounding points makes electricity more stable.

makes electricity more STABLE?! dude, are you serious?????? please only reply if you've got some useful knowledge.... :thumbdown

and grounds are NOT common.....for instance, there is a chassis ground, and an instrument ground, and a sensor ground in the car......ALL AT DIFFERENT VOLTAGE POTENTIALS FROM EACH OTHER.

[redturbo66]

Originally Posted by MrBoost

makes electricity more STABLE?! dude, are you serious?????? please only reply if you've got some useful knowledge.... :thumbdown

and grounds are NOT common.....for instance, there is a chassis ground, and an instrument ground, and a sensor ground in the car......ALL AT DIFFERENT VOLTAGE POTENTIALS FROM EACH OTHER.

Okay, tough guy.....you are an idiot. You obviously know nothing about electricity.
Do you know what an electrician is? I'm an electrician
Until you have something smart to add to this thread, keep your ass out of it. :thumbdown

[SpeedFreak03]

1) Would there be a problem with tying the 2 grounds together and putting that to a chassis ground INSTEAD of tying it to the ECU ground??

Well, for the SAFC (also uses 2 grounds on the ECU), the grounds are used to figure out some voltage, so the SAFC can 'trick" the ECU correctly. I guess its something similar with the AVC-R (maybe for correct RPM reading). So you do need both ECU grounds ON the ECU, I just dont know what they are there for, but I know APEXi uses them for something!

2) Why the heck are there 2 ground wires in the first place? What sort of a difference (voltage? potential?) is the AVC-R looking for?

I really don't know why the AVC-R would need them, but I can understand why the SAFC would. Maybe for RPM?

3) Does the AVC-R draw to much current for pin 92 (ground) of the ECU?

No it shouldn't, I know a few people running the AVC-R and they have no problems like that.

Anyway, MrBoost is right, redturbo, sorry man your wrong. In car electronics, all grounds aren't the same. Why do you think APEXi enginneers put those 2 grounds there? Im sure they had some reason. Why do you think mitsubishi (or any car manufacturer) doesn't just run a 2 gauge wire from the battery to the chassis, and ground everything to the chassis, instead of running ground wires? Now for a house, yea its all the same, but not in a car.

[MrBoost]

Originally Posted by redturbo66

Okay, tough guy.....you are an idiot. You obviously know nothing about electricity.
Do you know what an electrician is? I'm an electrician

hmmmm.......electrician eh??? well Mr electrician, I'm CU class of '02.......guess what my major was???.........ELECTRICAL ENGINEERING........yep, I'm an EE and I'm working on my master's right now. So, yeah, while I for sure DO NOT claim to be any sort of electrical genius, I do tend to know a *bit* about things such as voltage, current, resistance, inductance, capacitance, etc.

But give me a break man, "makes electricity more stable"????!!! Dude...get a grip, and define "electricity" for me......you talking about current??? voltage??? or just the flow of electrons???!

Wait, no, nevermind, please dont.... I really dont want to take the time to read another moronic response of yours.......


SpeedFreak03: thanks for the reply.........I really wish I knew what the potential difference between the grounds on the ECU is used for.....does the AVC-R trick the ECU at all?? (by allowing more boost than the stock BCS would??) I know boost is controlled by mechanical means in our cars, but I also know that boost pressure is one of the factors the ECU bases its fuel and timing calcs from...bah, who knows what the heck those kooky APEXi engineers were thinking when they developed the product....

I also wish I knew what the current overload was that happened to fry the ground track leading to the sensor ground (pin 92) of my ECU. Hmmm.........anyone else got any ideas what could have created this?? All I had hooked up was the AVC-R and the AFC.

Well, anyways, I guess I will just end up hooking it up like the manual shows, to ECU ground pin 26, with required spacing, of course.

[redturbo66]

Originally Posted by MrBoost

hmmmm.......electrician eh??? well Mr electrician, I'm CU class of '02.......guess what my major was???.........ELECTRICAL ENGINEERING........yep, I'm an EE and I'm working on my master's right now. So, yeah, while I for sure DO NOT claim to be any sort of electrical genius, I do tend to know a *bit* about things such as voltage, current, resistance, inductance, capacitance, etc.

But give me a break man, "makes electricity more stable"????!!! Dude...get a grip, and define "electricity" for me......you talking about current??? voltage??? or just the flow of electrons???!

Wait, no, nevermind, please dont.... I really dont want to take the time to read another moronic response of yours.......

Dear Mr. Electrical Engineer,
Congratulations on making it through 4 years of college. Have you had a chance to put any of that knowledge to work, yet? I've completed my schooling and I've been at my job for 5 years now. Are you experienced? I don't mean to embarrass you or anything like that but here's a question for you.
If I read from ground to ground on the same vehicle, I'll get continuity. Would that mean that the two grounds share a common ground?

Electricity-energy made available by the flow of electric charge through a conductor.

Is that definition good enough genius? Do us all a favor now and go kill yourself. :laugh: :laugh: :laugh: :laugh: :laugh: :thumbdown

[kpt4321]

Originally Posted by redturbo66

Dear Mr. Electrical Engineer,
Congratulations on making it through 4 years of college. Have you had a chance to put any of that knowledge to work, yet? I've completed my schooling and I've been at my job for 5 years now. Are you experienced? I don't mean to embarrass you or anything like that but here's a question for you.

Who gives a crap? He knows about potential difference, which you apparently do not. Theory is good enough is the vast majority of cases, the claim that real world experience is better is just something that people with improper knowledge try to pass off.

Electricity-energy made available by the flow of electric charge through a conductor.

And electricity flow from positive to negative, right? :thumbdown

Do us all a favor now and go kill yourself. :laugh: :laugh: :laugh: :laugh: :laugh: :thumbdown

You first.

[redturbo66]

Originally Posted by kpt4321

And electricity flow from positive to negative, right? :thumbdown

I don't remember saying that, jackass. Unless you've got something nice to say, don't say anything at all. Until then, go #### yourself.