01 dodge interped, pos. bat. cable shorted on eng. block, no start, 3.2eng

heyarn

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#1
someone just did a engine swap on this intreped(typical) the positive battery cable was shorting out on the enging block, i repaired the cable, charged up the batt, i tried to start, it spun, and fired rite up, ran for 3-5 seconds, then died, then it restarted, died again 3-5 seconds, now when i turn the key to start there is nothing, no clicks, nothing, starter is good, i can manually power it to spin the engine, i checked every fuse i could find, checked all ground cables, looking for possibly fuse links?? maybe the ecm is fried?? thanks for any help,,
 

nickb2

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#2
Did you bypass the relay in the relay center to get the starter to spin? If so check for circuitry from key switch to relay. If all is good, you may be looking at a fried starter relay control internal to PCM. But do check that circuit out. here is a diagram to help you.

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heyarn

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#3
thanks for the info, i'll check that relay , and wiring today, i did also have code po601, i was told by the owner the check engine light had been on for a while, and this cade had been present, now the check eng lite is out, always out, bulb maybe just burned out?? i'll check that too, thanks again
 

nickb2

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#4
P0601, this is not good news for you. This code is for internal controller failure. No fix available, must replace PCM!!! Here's the proof. Have to refalsh it after also. This should be a dealer job buddy. Sorry! :'(

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billr

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#5
Before replacing the PCM you might try reflashing it first. A friendly dealer might do that for a nominal fee if you promised them they would get the PCM replacement/reflash job if needed.
 

nickb2

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#6
I would tend to agree Bill, but my iffy feeling has got me, this guy is saying that engine was swapped and battery positive was swinging around and sparking all over on the engine block, good way to fry a PCM is to cause one too many spikes. It sure worth a try to reflash, but it's 50/50. I'm thinking a fuel pump driver has toasted in it, since it fired and ran on residual gas if I read the original post correctly. What do you think?
 

heyarn

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#7
i replaced the pcm, with a used one, i now know this won't work, the car starts rite up, than stalls in about 3-5 sec. it will do this 3 times, then nothing, no clicks nothing, security mode, so by replacing the pcm with a reman. pre-flashed assy. will this likely take care of the problem? is the security system built into the pcm, and does the bcm play a part in this too? thanks for any help,,
 

nickb2

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#8
Ok, please be clear on this for me, you just put in a used or re-manufactured PCM?
Is the security light flashing or on at all times?
There was no mention before of a security issue, that changes things dramatically from a diagnostic point of view.
Do you still have P0601? This is an internal PCM/ECM failure.
 

billr

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#9
Nick, I really don't think shorting the positive cable to ground could hurt anything but the battery or alternator; with one possible exception. If shorting that positive caused the alternator to go to "full output", then suddenly removing the short could cause a damaging over-voltage before the alternator regulator could respond. I mentioned that before in another thread. Getting back to the problem at hand, whenever I hear there is a security or remote-start system involved my eyes kind of glaze over. Those things seem to cause far more problems than they are worth. Let's hope "heyarn" will post back about the P0601 and ECM pedigree; as well as anything else that could be a clue.
 

nickb2

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#10
I don't know Billr, can't say I ever fried a PCM due to arcing, but sure do watch out when I weld. I sometimes even go so far as to unplug ECM connector before welding. I was always told this can be fatal. If that positive lead is striking a good ground sporadically, I could easily see a high amperage spike returning into ecm without fuse protection since it is severed. Maybe this is just an old wives tale I adhere to since I don't want to replace a ecm on my watch. I never really put any thought into it, I was always told to prevent any arcing of any sort, and I most certainly know how a battery blows up due to arcing, there are some serious amps involved here!! i'm not arguing, just saying I have always been under the impression that a circuit which has high amp or high current and it is arcing will maybe fry a ecm, look at a bad coil, seen many of those fry a ecm before, or a bad jumpstart, or a bad regulator or just plain high current causing enough heat to melt an already old solder connection. Anyways, this may be another post to debate.
We can only wait on this dudes answer to the question, is his security system on at this time?
 

billr

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#11
Nick, an additional concern with arc-welders, whether it be TIG, MIG, or stick, is that open-circuit voltage on those is considerably higher than 12V. I think 45-60V is fairly common, with the possibility that it is DC or AC.