|
|
87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
| |
|
|
WrecklessT
Novice
May 13, 2009, 1:54 PM
Post #1 of 14
(6860 views)
|
87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
I have recently had the ecmb fuse blowing no matter if the car is on or off. I can disconnect the negative from the battery and it still blows. I traced the orange wires to the ecm to find that the ecm (when tested on the orange connection points ) shows a short. The fuse doesnt blow when the computer isis unplugged so I am assuming the computer is bad. I am just inquiring if it could be anything else. I am going to get another computer todaybut I dont want to plug it in and blow it if you think it could be something else. I was thinking to install it with all the systems isunplugged(all the sensors and then slowly plug the sensors back in.
My other inquiry is there is a small blackbox hooked in line with the orange wires. It has a small computer board in it that can be slid out (kinda like ram on a computer but a little bigger) it has a battery hard wired in it and someother circuitry. Do you know what this is?
It also blows the ecmb fuse if it is plugged in by itself with the computer unhooked. Either one the computer or this black box when hooked to the orange wires (the fuel pump system) automatically blows. when I test the orange wires for ground problems with out the computer they all show fine. No grounding out .
So i can only assume that the computer and this other unit fried .
Ohh and this all happened when my brother in law went and pulled the battery out of my truck without my knowledge apparently to jump his vehicle> would this have ruined my computer systems. Like maybe he crossed the positive and negative or something. I would have thought that the fuse would go before the computers ??
Anyhelp would be appreciated.
(hyperlinks removed)
I have heard about the redundant fuel pump relay which apparently takes over from the relay after the vehicle is running. I can find very little information about this anywhere except it exists. I have also noted that on newer computers there is a little electrical box on the outside of the computers?? This could be exactly what my little black box is although mine isnt attached to the ecm..
I am desperate
Help
Todd
(This post was edited by Tom Greenleaf on May 18, 2009, 7:03 PM)
|
|
Attachments:
|
IMG_1867.JPG
(11.6 KB)
|
|
| |
|
|
autojoe
User
May 14, 2009, 6:47 AM
Post #2 of 14
(6840 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
the fuse should have protected ecm.what size engine?I have all wiring diagrams.
|
|
| |
|
|
WrecklessT
Novice
May 18, 2009, 1:02 AM
Post #3 of 14
(6827 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
Greetings and thanks for the help so far..
I know the fuse should have saved me but it didnt. I put in new computer and the fuel pump now starts when i turn the key for priming. My problem is the little black box with the computer board in it. It is hooked in right by the computer and if you follow the orange wires from the ecmb they are all tied together to the fuel relay and this black box (the box has a few wires in it aqnd they run to the computer and one out to somewhere. it is weird but from the diagram i could find one of the wires from the blacvk box seem to go into the computer at the IAC connection// cant be right. Anyhow this black box was also blowing the fuse every time i hooked it up to the harness so i havent plugged it back in and I dont want to unitl i know what it is. I have included a picture of it and maybe you can see it on a wiring diagram
This is the 2.8 litre 4x4 by the way
Thanks for any help you can give
TODD
|
|
| |
|
|
WrecklessT
Novice
May 18, 2009, 1:10 AM
Post #4 of 14
(6826 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
 There is the picture of the part i am trying to identify The computer chip has been removed by me to show it better it just slid3es right in and clicks in place like computer ram ansd has a battery hard wired to it so I assume it must have memory of some sort or maybe a timer?? to run the fuel pump I jusdt cant get an answer anywhere asd to what this is and what it does.. ??????Redundant Fuel Pump Relay Circuit??????? Apparently a redundant circuit takes over from the fuel relay after you are up and running ..Is that what this is and if so Why does no one know anything about it??
:HELP I cant find it on the wiring diagram I have but this wiring diagram i have is probably from a new model or the truck instead of my model s15 jimmy 2.8 litre 4x4
HELP
Thanks
Todd
Todd
|
|
| |
|
|
autojoe
User
May 18, 2009, 5:05 AM
Post #5 of 14
(6821 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
looks like the old spark control module but it is not.
(This post was edited by autojoe on May 18, 2009, 2:05 PM)
|
|
| |
|
|
autojoe
User
May 18, 2009, 6:05 AM
Post #6 of 14
(6813 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
dug out some old old books.......This is a e-cell chip that was active during the break in period in which altered certain parameters.It would expire after the break in period.
(This post was edited by autojoe on May 18, 2009, 2:03 PM)
|
|
| |
|
|
autojoe
User
May 18, 2009, 11:56 AM
Post #7 of 14
(6808 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
The wires that go to it..........1)orange....2)pink/black.........3)dark blue/white?
(This post was edited by autojoe on May 18, 2009, 2:04 PM)
|
|
| |
|
|
autojoe
User
May 18, 2009, 2:07 PM
Post #8 of 14
(6800 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
Drive vehicle with it disconnected and removed.
|
|
| |
|
|
WrecklessT
Novice
May 18, 2009, 5:43 PM
Post #9 of 14
(6786 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
THanks Joe,
I looked every where I still cant find info on ecell. What the heck did it do and it wont be a problem driving without it??
My fuel pump is running now when I turn the key but I have not started her yet as I was worried about this part.
So tomorrow I will put it all back up and fuel up and start her running. If you know of anyproblems this may cause please let me know and again thanks for your time you are a life saver..no other site had anyone who knew anything about it so far..In fact I was called crazy at one and that this part wasnt in my truck?? to funny like I found a part and decided ro just post it to have fun??
Crazy..
Anyways I really would like to know what it was this chip did just for my own info.. I have never seen one before. WAs it a chip to increase fuel or power >??? I dont care if thats what it was I dont want it anyways..Or when you say burn in it was for the initial break in of the system ?? It would seem logical considering that the battery wired to it had to eventually die and then what..
Ok have a great day
Todd
|
|
| |
|
|
autojoe
User
May 19, 2009, 9:12 AM
Post #10 of 14
(6776 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
I imagine it would alter maybe the timing and maybe fuel enrichment.I thought at first it was a esc module and then when I seen the circuit board I knew it was not that.I looked up in old book and noticed the e-cell.I never seen one before so I emailed a friend and he knew what it was.Should not be any problems driving without it.I worked on a lot of older gm vehicles even way before that and never remember seeing that before.Probably only used a couple times and only used by GM.
|
|
| |
|
|
WrecklessT
Novice
May 19, 2009, 11:54 AM
Post #11 of 14
(6771 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
Thanks Joe
YEah it plugs in series with the computer and this is the first year gm had the computer in the Jimmy I looked at an 88 gmc jimmy and it is different in that this part isnt there. I know that on all the computers i looked at there was a small box attache to the computers and they had wires in them but it was actually attached to the ecm on the side you have probably seen them (I am sure you have).
I am only a little concerned as I have to pass air care again but I guess I will just have to go for it..
Take care
PS do you know anything about the transfer case in these. I put iot into four wheel drive and it gears down and if I am rolling down the hill you can fel that the sytem is in 4 lo because it crawls and revs out real easy like it should but the front tires arent turning??
I thought it was the vaccuum line and it could be but if it was the vaccuum it would not go into that low gear would it or is the vaccuum what engages the drive chain for the front wheels>> I dont know how to check , I heard youi can just manually pull the vaccuum actuator and engage four wheel drive??
ANy info ... THis is not overly important as I only use the 4 wheel in the snow (well i would only if I could get it engaged properly
|
|
| |
|
|
autojoe
User
May 19, 2009, 3:32 PM
Post #12 of 14
(6764 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
I wish I could help but don't know much about transfer cases.Maybe post on this site and someone might be able to help you.
|
|
| |
|
|
hotrod682
New User
May 18, 2011, 1:15 AM
Post #13 of 14
(5659 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
If u haven't figured it out yet I had the same problem with my gmc 87 s-15 2.8 v-6 the same fuse blew on me. Its not your computer the short is in your fuel pump and sending unit circuit. Atleasr it was with my vehicle. I hope this helps u
|
|
| |
|
|
Hammer Time
Ultimate Carjunky
/ Moderator
May 18, 2011, 5:27 AM
Post #14 of 14
(5651 views)
|
|
Re: 87 GMC s-15 JIMMY ECM b fuse and ...
|
|
|
This thread is 2 years old. Please look at dates before posting.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
|
|
| |
|
Auto Repair Home
SEARCH
WHO'S 
LOG 
2011 Dodge Nitro OBD scanner seems to drain battery in 10-20 minutes
Grounding Cable, 2017 Jeep Renegade Trailhawk
Howdy
