ECM failure

[BLACKRAM]

The tech that caused a small spark on the battery ended up frying the ECM. I took it to the dealer to look for codes (I thought it might be a bad cell in the battery or a fuse).

Well now we find the ECM is toasted, and the charging system won't work. #ad


The driveablity is great except for the charging system, so I don't think the BOMBing had anything to do with it. Lucky for me the Tech at the Dodge dealer reads the TDR!

Anybody have a similar ECM problem before?

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1999 2500 4x4, auto, 3. 54 LSD, HD241, Quad cab SLT, Blk Sport Pkg, 16x8 Eagles, 285 Bridgestone AT, 100% Amsoil, 80/100w lights, Valentine One, DTT TC/vb, Mag-Hytek trans pan, DD2's, DD TTPM, Isspro gauges.
1992 SC400
1978 Mooney 201 IFR

 

[MikeR]

Did you look at the underhood fuse box and check to see if the big 140 amp fuse is blown? When someone zaps a battery or the back of an alternator,this fuse usually blows,then the charging system doesn't work.

How can the drivability be great if you say the ECM is fried?

-Mike

 

[americana]

my ecm was fried for a while before i had it replaced and drove famously (except that the tach was usually dead and it didn't want to re-start when warm/hot). there is a default/failsafe that the engine falls back on when the brain goes. wouldn't it be great if we had the same back up system?

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regards,

peter
1998 24v 4x4 QC, SLT, Sport, Leather, Linex, snug lid, center line wheels, Smittybilt side steps,color matched fender flares, stull grills, tow hooks----first diesel, dodge etc. i'm in love!

FREE CARL!!

[This message has been edited by americana (edited 03-30-2001). ]

 

[Shovelhead]

One of the functions of the ECM on our trucks is voltage regulator.
Had a gasser that fried the voltage regulator portion of the ECM, otherwise there was no problem. It started, ran fine, but would not energize the alternator to recharge the battery.

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Ed Anderson
99 3500,QC,Auto,4. 10,Everthing 'cept leather,stock until warranty runs out.
'76 H-D FLH, '98 FLHTCUI

 

[BLACKRAM]

Final cause was the alternator, not the ECM or a fuse. It is fixed and back to normal. The BOMB mods had nothing to do with the problem. A spark from a tech touching the battery caused it.

The moral of the story: Disconnect the battery before doing any work in the engine compartment.

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1999 2500 4x4, auto, 3. 54 LSD, HD241, Quad cab SLT, Blk Sport Pkg, 16x8 Eagles, 285 Bridgestone AT, 100% Amsoil, 80/100w lights, Valentine One, DTT TC/vb, Mag-Hytek trans pan, DD2's, DD TTPM, Isspro gauges.
1992 SC400
1978 Mooney 201 IFR

 

[BLACKRAM]

Well, I thought it was fixed. The alternator and both batteries were replaced. The truck drove fine, but the voltage continued to read low. It starts getting dark, so I turn the lights on and the "check gauges" light comes back on. The mechanic who did the work reads the TDR and is a 5 star dealer.

Anyway, I'm screwed. #ad


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1999 2500 4x4, auto, 3. 54 LSD, HD241, Quad cab SLT, Blk Sport Pkg, 16x8 Eagles, 285 Bridgestone AT, 100% Amsoil, 80/100w lights, Valentine One, DTT TC/vb, Mag-Hytek trans pan, DD2's, DD TTPM, Isspro gauges.
1992 SC400
1978 Mooney 201 IFR

 

[Joseph Donnelly]

Sometimes a fuse looks OK but is bad. Otherwise, I guess you have eliminate everything but a roasted wire or fusible link, or the ecm. Check the wires for continuity, then swap the ecm. My friend at the dealership told me there have been some bad ecms recently.

 

[BLACKRAM]

Well, another trip to the dealer and now it is fixed. It seems the alternator was bad, and replaced, however the problem still occured. When the tech shook the wire harness, he noticed a spark at the power control box. The 140 amp fuse had blown, but had welded itself back together. This is why it worked some of the time. Now the guage is back to normal, and the truck is fine.

Moral: Disconnect the battery before work on the engine!