[Clutch5sp]

Watching Scanny Danny with lessons on checking the 5volt reference that may help steer me where the problem is. It's beating me up guys....It's beating me up.

 

[pbfoot]

At this point I would pull the ecu/pcm and open the cover and check for a burnt circuit.

 

[Clutch5sp]

At this point I would pull the ecu/pcm and open the cover and check for a burnt circuit.

Want to check the 5v reference at TPS per Scanyerd Danyerd on YT instructions. A clue....any clue is a step closer to solving the prob. At this point, the pcm could easily be yanked out and dissected like a frog. Still nothing found burnt.

 

[pbfoot]

Normally I would look at the radio interference module on the coil pack bracket but when that shorts it usually blows the 20amp engine management fuse. It is going to be something simple. Ecu failures are very rare but not unheard of.

 

[Poor Focus]

My 2004 would not start. Had it towed. Mechanic found a post factory remote starter kit had been installed by previous owner (I did not know it was in there) and it had failed.

 

[Clutch5sp]

I had to explore today and look what was found....2-pieces of metal rattling around inside the PCM case and the smell of burnt electrical was found on the board. Do I chance getting another PCM and this happening again OR assume the slag has been in there since the car was new and finally found a short?

 

[amc49]

The green board with the rectangle chip next to a round thing. Above the chip...is that dark spot a burn spot? If so the PCM is likely dead.

 

[pbfoot]

I had to explore today and look what was found....2-pieces of metal rattling around inside the PCM case and the smell of burnt electrical was found on the board. Do I chance getting another PCM and this happening again OR assume the slag has been in there since the car was new and finally found a short?
View attachment 318680

Kind of figured that would be it after you said you smelled burn when you unplugged it. Any aftermarket stereo installed before this happened? If not I think you may need ok and it was just a badly assembled pcm

 

[Clutch5sp]

Kind of figured that would be it after you said you smelled burn when you unplugged it. Any aftermarket stereo installed before this happened? If not I think you may need ok and it was just a badly assembled pcm

No aftermarket nothing on this ole virgin cept the tires. Yep...had the 104-pin connector loose so I thought...Hmmm pbfoot wanted to have a peek inside the brain box. It was really easy to get out then I heard the rattly bits inside. No connector area was burnt. Smelled it first....I would have bet my only testical that my prob was just inside that cover...YEP

I found an exact match PCM on egay ($35) and it's on the way. Ya think my Forscan software can recombobbulate the used pcm to work? If not, what needs to happen and how much does this service cost....abouts?

 

[Clutch5sp]

Here's a better pic...

 

[pbfoot]

No aftermarket nothing on this ole virgin cept the tires. Yep...had the 104-pin connector loose so I thought...Hmmm pbfoot wanted to have a peek inside the brain box. It was really easy to get out then I heard the rattly bits inside. No connector area was burnt. Smelled it first....I would have bet my only testical that my prob was just inside that cover...YEP

I found an exact match PCM on egay ($35) and it's on the way. Ya think my Forscan software can recombobbulate the used pcm to work? If not, what needs to happen and how much does this service cost....abouts?

I think so. You just have to marry your key to the new pcm. I've never done it myself but there should be someone on here that knows. Last but not least a mobile locksmith can do it.

 

[pbfoot]

Did you replace the battery cables yet? Possible the cable rubbed through and caused the short but I'm thinking a fuse should have stopped any current from getting that far.

 

[Clutch5sp]

Yes...I installed the new batt cable assembly. No sign of anything shorted, but the last bit of positive wire (4") starter to alternator was weird like it got hot over time. The metal pieces found in the PCM were like slag from welding. Each BB sized piece did have a very tiny spot like it was attached to something at one time. When they came loose, it was right to the spot burned on the board. POOF...no worky worky

 

[pbfoot]

Yes...I installed the new batt cable assembly. No sign of anything shorted, but the last bit of positive wire (4") starter to alternator was weird like it got hot over time. The metal pieces found in the PCM were like slag from welding. Each BB sized piece did have a very tiny spot like it was attached to something at one time. When they came loose, it was right to the spot burned on the board. POOF...no worky worky

Who knows. Fingers crossed.

 

[Poor Focus]

@ Clutch5: Nice job! THANK YOU for posting the "Solution" as that is so rare to find on these types of threads.

 

[Clutch5sp]

@ Clutch5: Nice job! THANK YOU for posting the "Solution" as that is so rare to find on these types of threads.

Didn't want to be that guy who...

Still not out of the woods yet. Must learn if my Forscan software can get the replacement PCM setup. If not, there must be someone available who can do the programming or maybe I gotta tow it to the dadgum dealer as a very last resort. Also, there could very well be some other issue besides the freak loose metal found rattling around inside the PCM case causing it to short out & burn the board.

 

[Clutch5sp]

Removed the other side PCM cover to see more stinky burnt shtuff. Looks like pin# 71 & 97 are melted if I'm looking at this correctly. This needs to be explored. Any ideas...?

 

[Poor Focus]

If that is directly behind the other burns, and if this picture is upside down, I'd say that there was a short on the board, an overheat condition, and the heat rose to affect other parts of the board as the charring seems to flow from top to bottom (or rather upward assuming the picture is upside down). I believe a short started it and not an overvoltage as an overvoltage tends not to have smoldering conditions as evidenced by the burnt greenboard, but rather more of a "once and done" failure which would have exploded components and have relatively minimal charring. I could be wrong, but I base my opinion on what I saw in fire alarm and communication boards when I was a field tech. Therefore, replacing this board is a good place to start HOWEVER... Have a dealer install it. Why? Because if YOU install it AND the original cause was external to the PCM (in the car itself) then you will blow up the new board. If this happens to the dealer, the dealer will have to eat the new board although you may have to pay for them to find the external cause (if it exists). Your call... you have 10 seconds to make a decision, or we kick you off the forum. Just kidding. I sincerely wish you well in this predicament.

 

[Clutch5sp]

When I checked powers & grounds, this was done at the connector. There was power to pins #71 & #97. From the diagrams on CHARM these pins are the main feeds to the PCM from the powerhold relay fuse circuit F9 20amp. I lightly scrubbed around on the board to see mainly the copper paths gone from the circuit board.

Is it possible to put some new jumpers all down up in there from pins to board and see if it works again? The area where the board burnt backside solder point is like a mini nuke went off on the pin. This shows the least path area...right? It blew all at once even the green board crumbles to powder where the pin was. Why didn't the fuse blow?

Here's another clue...the inside of the car had that weird electrical smell (past years or so)not strong or overpowering in any way. The day it blew was unmistakable burnt electrical with a hint of fertilizer wiff.

These 71 & 97 circuits need to be explored to find what caused the short before any new pcm is hooked up. The car is virgin in every way no stereo alarm sys nothing....Stone stock.

 

[Poor Focus]

1) I would not trust the board. Do not repair it. The electronic componants are most likely shot even if they look good. 2) It is possible that an internal short fried the board but did not draw enough curren to take out the fuse. 3) If F9 is good, and there is voltage at the pins 71 and 97 of the harness, then the feed circuit is likeley good. Additionally, a short in the harness is not what fired the board (in my opinion). 4) soemthing has been overheating for a long time and finally got hot enough (due to increassed current as things progressively got worse) to finally cause the fatal heat damage and ultimate failure.