ECM Randomly Losing Power?

[BoostMasterK]

I have long suspected that my ECM resets itself and today I finally "caught" it.

I just had the A-arm bushings replaced so I was test driving it. I stopped the engine a few times to get gas and stuff and it was still learned in. Then on the last leg of my drive I took some hard curves on the way home, parked the car and when I restarted it, all my BLMS were reset.

I tested the orange wire from the battery to the harness, jiggled the (heck) out of it and it was fine.

Before I rip out the ECM to jiggle every power and ground, has anybody ever seen this problem before?

TIA,

Mike [

 

[zam70]

I'd plug and unplug the ecm a few times...might have some corrosion on the pins.

 

[GN Bob]

My fuel pump wasn't priming before startup, pulled the ECM connector and found the pins covered with corrosion.

Pull the connector and look for white corrosion on the B+ pin.

Get some electronic contact cleaner, spray both plugs and all the pins, while still wet, plug and unplug several times.

This should do it.

Eat some Basturma, breath deeply on the ECM and go for a ride.

Good luck

Bob Mourachian

 

[BoostMasterK]

Originally posted by GN Bob
....Pull the connector and look for white corrosion on the B+ pin....Eat some Basturma, breath deeply on the ECM and go for a ride...Bob Mourachian

Thanks for the tip, but they have laws against chemical weapons now


Mike [

 

[jastrckl]

Right before my ignition module went out completely, noticed something was resetting my ecm when I looked in DS logs. I chased grounds for a while, took until the car eventually consisently coded module before I fixed it and all of the problems went away.

 

[BoostMasterK]

NTF

I opened the ECM connection and no corrosion seen with a flashlight and magnifying glass I flooded it with QC2000 and cycled the connector anyway.

I jiggled the harness on both sides of the firewall and backup/ground did not cut out on the meter. I closed it all up, and shook the ECM, harness, and the whole car...no reset.

I probably should have done all that jigglinh BEFORE I opened the connector I guess I have to wait to see if it happens again. I hope it's not the ignition module.


Mike [

 

[c&cgn]

Re: NTF

Originally posted by mkazigian
I opened the ECM connection and no corrosion seen with a flashlight and magnifying glass I flooded it with QC2000 and cycled the connector anyway.

I jiggled the harness on both sides of the firewall and backup/ground did not cut out on the meter. I closed it all up, and shook the ECM, harness, and the whole car...no reset.

I probably should have done all that jigglinh BEFORE I opened the connector I guess I have to wait to see if it happens again. I hope it's not the ignition module.


Mike [

You don't happen to have Directscan do you? Sounds alot like a DS gremlin that I had last year. Unplugged DS from the ecm and it fixed the problem. Since then I have cleaned up the connection and really sheilded the DS cable and I haven't had a problem so far this year, but I haven't diriven it much yet. Just something to consider.

 

[BoostMasterK]

Re: Re: NTF

Originally posted by c&cgn
You don't happen to have Directscan do you? Sounds alot like a DS gremlin that I had last year. ...

Yes Clayton, I do. I thought this was happening before then, but now that I think about it, I would probably require Direct Scan to see the BLM tables to be aware of it

There is a mention of erratic behavior on the DS web page and they recommend shielding the cable. How did you shield yours?

Thanks!

Mike [

 

[c&cgn]

Tin foil. Lots and lots of tin foil. So far so good since I've done it.

BTW, it doesn't matter whether you have your laptop hooked up or not since the cable from the ECM is hooked up at all times. The way I figured it out was a tip from Bob Bailey about DS gremlins so I tried unplugging DS from the ECM for a few days and all of the mysterious little problems I was having disappeared. Since I have sheiled the cable now I am going to try leaving it hooked up permanently and we'll see how it goes.

 

[BoostMasterK]

Cool, I'll have to try it.

What other problems did you have? Did you ground the foil?

THanks!

[

 

[86underboost]

Does the ses light flash when it happens?? Does ds show 0 volts for a split sec?? Chech the positive batt cable for a bare spot...i've seen it a bunch of times

Ya said it happened after the control arm bushings?? The cable is right there!!!!!

just a thought

 

[BoostMasterK]

Originally posted by 86underboost
Does the ses light flash when it happens?? Does ds show 0 volts for a split sec?? Chech the positive batt cable for a bare spot...i've seen it a bunch of times

Ya said it happened after the control arm bushings?? The cable is right there!!!!!

just a thought

Thanks Mike. I jiggled the hell out of that connection but I'll give it another look


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