interested in your result
Repairing ECM pigtail
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
Repairing ECM pigtail
The engine harness pigtails that plug directing into the ECM (2 of them for the 165 ECM) are loose and several wires are intermittently losing continuity. The metal pins inside the plastic connector are themselves the problem as they move around enough to break the connection (if all this makes sense).
So, who has tips on how to repair the ECM pigtails without cutting 40+ wires and soldering on a new pigtail? It is a major PITA as various sensors will go in/out as the wires are jostled - makes tuning a real bear... lol.
So, who has tips on how to repair the ECM pigtails without cutting 40+ wires and soldering on a new pigtail? It is a major PITA as various sensors will go in/out as the wires are jostled - makes tuning a real bear... lol.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
wow.
I would try to pinch them... or perhaps some kinda glue to set them into place.
The 165 ECM? What year is that? I don't remember.
You may want to check into a new harness if the car is pre 1990.
I would try to pinch them... or perhaps some kinda glue to set them into place.
The 165 ECM? What year is that? I don't remember.
You may want to check into a new harness if the car is pre 1990.
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
it's an 84 with an 86' harness and ECM. The engine harness was "reworked" with many new sensors during the conversion - but this popped up about a year ago. I suppose I could get a new harness - but I'd really not like to have to pull everything apart for what should be an easy fix.
I can hook up my datalogger and see sensors drop in/out as I play with the wires at the ECM, so that is definitely the problem. No other issues really, so I'd rather not spend $300+ on a "new" harness. Not sure if Painless does the 165 engine harness or not...
I can hook up my datalogger and see sensors drop in/out as I play with the wires at the ECM, so that is definitely the problem. No other issues really, so I'd rather not spend $300+ on a "new" harness. Not sure if Painless does the 165 engine harness or not...
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
It sounds like the "combs" are missing from the back of the connectors. The "combs" are flat plastic pieces that go in from the back and lock in place and secure the pins to keep them tightly held in place. Check your harness connectors and make sure they are there.
If you can't find them post back and I'll try to take a picture of them and send it to you.
If you can't find them post back and I'll try to take a picture of them and send it to you.
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
the combs are there. I even removed them to look more closely at the connectors. The pins out of the ECM are simply too long for there NOT to be a connection with the female side / the actual pigtail connector - so I'm going to try some of that anti-corrosive stuff someone on the forum mentioned last week. It's either not getting a clean metal-metal connection or perhaps the friction fit of the female (pigtail side) part of the connectors could be worn enough to make it lose. I'll have to see about trying to get some "spring" back in them if that is the case.
I'll post what I find - right now my money is on the pins/connector being slightly corroded.
EDIT: this is the thread I was referring to. I'm hoping it will solve my problemo!
http://forums.corvetteforum.com/show....php?t=1247196
I'll post what I find - right now my money is on the pins/connector being slightly corroded.
EDIT: this is the thread I was referring to. I'm hoping it will solve my problemo!
http://forums.corvetteforum.com/show....php?t=1247196
Last edited by Ramanstud; Jan 8, 2006 at 12:42 AM.
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Burning Brakes
Joined: Jul 2003
Posts: 904
Likes: 36
From: Santa Cruz CA
replace the terminals
If you use the red handle delphi depinning tool, push from the ECU side and you can pull the wire and terminal out the back side. You can then see the condition of the terminal. If they are worn out just order new ones and crimp them on and reinsert into the connector. Take the combs out of course before removing or they never come out. It can take some force to get them to come loose sometimes but just push from the ECU side of the connector and they will pop out the back and you can do whatever you need to do to fix them. They are metri-pack terminals if you need to get replacements somewhere if they are just worn out.
Safety Car
Joined: Feb 2002
Posts: 4,212
Likes: 10
From: Sun City West Az
Originally Posted by Jaxian
If you use the red handle delphi depinning tool, push from the ECU side and you can pull the wire and terminal out the back side. You can then see the condition of the terminal. If they are worn out just order new ones and crimp them on and reinsert into the connector. Take the combs out of course before removing or they never come out. It can take some force to get them to come loose sometimes but just push from the ECU side of the connector and they will pop out the back and you can do whatever you need to do to fix them. They are metri-pack terminals if you need to get replacements somewhere if they are just worn out.
Large Impressive Member
Joined: Jul 2003
Posts: 65,811
Likes: 71
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by Jaxian
If you use the red handle delphi depinning tool, push from the ECU side and you can pull the wire and terminal out the back side. You can then see the condition of the terminal. If they are worn out just order new ones and crimp them on and reinsert into the connector. Take the combs out of course before removing or they never come out. It can take some force to get them to come loose sometimes but just push from the ECU side of the connector and they will pop out the back and you can do whatever you need to do to fix them. They are metri-pack terminals if you need to get replacements somewhere if they are just worn out.
I've not had to do this on my Corvette yet but have on many other vehicles. With the right tools, it's not difficult.
Thread Starter
Melting Slicks
Joined: Oct 2002
Posts: 3,193
Likes: 1
From: Cincinnati Oh
FIXED
I applied the Deoxit cleaner and then the Deoxit Gold stuff from radioshack. at first, no change.
I kept playing with the oxygen sensor leads while datalogging (to see if the sensor data was active or disconnected when I moved it) - it would pop in and out for the first few "jiggles" and then it stayed on. I experimented quite a bit and it seems to have "set" now. I guess I just didn't physically rub the leads enough to remove the corrosion. I did this with the few sensors that have continually been problematic - and everything seems "go" on a test drive with plenty of bumps and jostles.
So, in my humble experience, the de-oxidative "stuff" seemed to work with a little attention to making sure the leads are clean by repeatedly plugging/unplugging the connectors.
EDIT: also, the individual leads in the ECM pigtail will still move a little - but I think that's expected to some degree as it doesn't break the connection at all. So removing the leads and replacing them appears to be unnecessary at this time.
I applied the Deoxit cleaner and then the Deoxit Gold stuff from radioshack. at first, no change.
I kept playing with the oxygen sensor leads while datalogging (to see if the sensor data was active or disconnected when I moved it) - it would pop in and out for the first few "jiggles" and then it stayed on. I experimented quite a bit and it seems to have "set" now. I guess I just didn't physically rub the leads enough to remove the corrosion. I did this with the few sensors that have continually been problematic - and everything seems "go" on a test drive with plenty of bumps and jostles.
So, in my humble experience, the de-oxidative "stuff" seemed to work with a little attention to making sure the leads are clean by repeatedly plugging/unplugging the connectors.
EDIT: also, the individual leads in the ECM pigtail will still move a little - but I think that's expected to some degree as it doesn't break the connection at all. So removing the leads and replacing them appears to be unnecessary at this time.
