Bad ECM?
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
Bad ECM? I have a 2000 WS6 and randomly it feels like someone unplugs a few plug wires when driving. It may last 5 seconds or 5 miles and then all the sudden it runs perfect again. At times the CEL will come on, and sometimes not. I pulled code P0200 for FI circuit. I just recently swapped the LS1 out for a new LS3 set up and it still does this. The only thing used on the new set up was plug wires and FI adapters...I changed wires and swapped out all the EV1-EV6 adapters and checked wiring the best I could for a ground somewhere...I have read it could be the ECM itself. I can not get the car to act up while its at the house to use my noid lights. I have checked the ohms on the injectors and they are all pretty close. I have looked on rock auto to get a replacement ecu but not sure which one it the correct one....They have AC Delco 21811789 (19109040) and 21812290 (19143656) ....What are the odds of this being the ecm and not just a wire being grounded out at times?
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
Bad Computer? Posted this in the PCM section, but no responses...So maybe someone here will know or have had this issue...
I have a 2000 WS6 and randomly it feels like someone unplugs a few plug wires when driving. It may last 5 seconds or 5 miles and then all the sudden it runs perfect again. At times the CEL will come on, and sometimes not. I pulled code P0200 for FI circuit. I just recently swapped the LS1 out for a new LS3 set up and it still does this. The only thing used on the new set up was plug wires and FI adapters...I changed wires and swapped out all the EV1-EV6 adapters and checked wiring the best I could for a ground somewhere...I have read it could be the ECM itself. I can not get the car to act up while its at the house to use my noid lights. I have checked the ohms on the injectors and they are all pretty close. I have looked on rock auto to get a replacement ecu but not sure which one it the correct one....They have AC Delco 21811789 (19109040) and 21812290 (19143656) ....What are the odds of this being the ecm and not just a wire being grounded out at times?
I have a 2000 WS6 and randomly it feels like someone unplugs a few plug wires when driving. It may last 5 seconds or 5 miles and then all the sudden it runs perfect again. At times the CEL will come on, and sometimes not. I pulled code P0200 for FI circuit. I just recently swapped the LS1 out for a new LS3 set up and it still does this. The only thing used on the new set up was plug wires and FI adapters...I changed wires and swapped out all the EV1-EV6 adapters and checked wiring the best I could for a ground somewhere...I have read it could be the ECM itself. I can not get the car to act up while its at the house to use my noid lights. I have checked the ohms on the injectors and they are all pretty close. I have looked on rock auto to get a replacement ecu but not sure which one it the correct one....They have AC Delco 21811789 (19109040) and 21812290 (19143656) ....What are the odds of this being the ecm and not just a wire being grounded out at times?
ECM is not likely, i mean it can happen but its the unusual.
did you use the harness on the ls3? Id probably check the power wires, they can corrode over time and they wont distribute power the as well (the mains from the battery starter and fuse relay). Also how is your battery voltage at idle? when I did my swap I had to repin the alternator connector as it wasnt charging.
did you use the harness on the ls3? Id probably check the power wires, they can corrode over time and they wont distribute power the as well (the mains from the battery starter and fuse relay). Also how is your battery voltage at idle? when I did my swap I had to repin the alternator connector as it wasnt charging.
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
I used the same wiring harness that was on the LS1...it did it a few times before the swap, but it had not done it in months before. I checked over the wiring as good as I could and didn't see anything out of the ordinary. Voltage is spot on at idle and driving, but didn't really pay attention to voltage when it would fall flat. Alternator was replaced with a new one a couple months before the swap also.
ok Id pull the terminal covers for your main power and ground wires and check for corrosion that,s most likely the culprit especially if it exhibited the same symptoms pre swap ( just an old age issue) . If its there you will have to replace the whole wire. Look into " the big 3" mod. Refers to replaceing the power and ground wires with larger gauge wire. It likely wont show on just the eyelet ring you may need to expose some of the wire core.
I actually had a similar issue before my swap and it was one ff he wires coming out of the main battery terminal. When I wiggled the terminal the issue went away, didnt realize it was corrosion till I did the swap.
I actually had a similar issue before my swap and it was one ff he wires coming out of the main battery terminal. When I wiggled the terminal the issue went away, didnt realize it was corrosion till I did the swap.
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
I will take a look for sure. I know the main post on the battery are very clean and tight. I thought maybe a wire that runs in the harness down the pass side down past the headers may have gotten burned or touching the header but the wire loom was closed and no signs of melting or anything from the headers...Im going to take it to the performance shop that has done all my work and get him to take a closer look. After 4 back surgeries and about to have another, I can only bend over the hood for a few seconds at a time. Im not sure if any of the wires or connections in the 2 fuse boxes on the front drivers side have anything to do with the FI harness, or if they can even cause this issue if corroded etc...
its not anything in the fuse relays them selves but there is a 4 guage power wire that loops into it (brass terminal with red cap one one of the boxes) I think it originates off the alternator. The main power off the battery touchs the alternator and starter. they are part of how the whole system maintains the 12v loop along with the grounds. So if you sever a connection or damage it (corrosion) it can maintain until it hits its load limit which depends on the level of corrosion or damage. When I had the alternator problem mine was fine until I hard accelerated. when I had the corrosion issue, it would always give me problems at stop lights.
Probably was fine until the harness started to get moved around and knocked the corrosion loose and made the problem more prominent.
One easier less stressful method on your back would be to start the car, turn the high beams on hit the brakes, turn up the stereo and AC and rev the engine. If it falls on its face with that much load on the system it would be a good indicator.
Probably was fine until the harness started to get moved around and knocked the corrosion loose and made the problem more prominent.
One easier less stressful method on your back would be to start the car, turn the high beams on hit the brakes, turn up the stereo and AC and rev the engine. If it falls on its face with that much load on the system it would be a good indicator.
Trending Topics
Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
I have done that, voltage stayed the same but it was also running fine when I had everything turned on. I just cant get the car to act up when its at home to see which bank or FI are not firing with the noid light, or ohms drop on the injectors themselves..
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Launching!
Joined: Jan 2016
Posts: 224
Likes: 1
I finally got it to act up at home...I wiggled the wire loom that runs down the pass side down past the headers and it cleared up. I wiggled them again and it went flat again, so at least I know its in the wiring loom somewhere. Thanks for all the advice!