Van Mechanical Issues Are Taking the Wind out of My Sails

[SternWake]

PM sent with phone #.

 

[SternWake]

I sent the photo of the burnt looking pcm potting to my electronics tech friend and asked his opinion on the coloring representing component failure, or not.

Hope the rangers are not giving you too much grief. Sorry you are completely stranded.

here is the connector/ circuit board connection which gave me so much grief:

 

[SternWake]

Here is the connector I foolishly declared pristine after cleaning it with CRC QD cleaner:

You can just see the little spring claspers inside the sockets.

After I got the Deoxit, the d5 saturated swabs I used in this cleaned connector turned black and got shredded as if it was 220 grit sandpaper and after the caig D5 application the insides of those sockets gleamed and felt like oiled chrome. the 14 sockets shredded 6 precision swabs and turned them black. the 7th swab was rerun though every socket again and came out in perfect condition and still pink colored from the D5.



Still took a sewing needle and bent the claspers inwards to grab the pin with more pressure.

 

[drewker]

sorry for the big letter typing guys and the duplicate posts. i'm using a combo of wifi hotspot on my laptop and cell phone typing which is prone to errors. status is still the same, about to make some phone calls when things open and likely walk 8 miles up the road to watsonville as there is not much of a town where i'm at. if anybody knows for certain a place that i can ship a package to that would be very helpful. sternwake said check ups store or po which i will, but they may require you to sign of for a po box first. i am sure i can get the part much cheaper on ebay or lkq than autozone or oreillys but outside of a local junkyard having the part (which is a real long shot that they have the exact part i need in good condition) the part will likely have to be shipped. over and out....

 

[drewker]

Here is the connector I foolishly declared pristine after cleaning it with CRC QD cleaner:

You can just see the little spring claspers inside the sockets.

After I got the Deoxit, the d5 saturated swabs I used in this cleaned connector turned black  and got shredded as if it was 220 grit sandpaper and after the caig D5 application the insides of those sockets gleamed and felt  like oiled chrome.  the 14 sockets shredded 6 precision swabs and turned them black.  the 7th swab was rerun though every socket again and came out in perfect condition and still pink colored from the D5.



Still took a sewing needle and bent the claspers inwards to grab the pin with more pressure.

man that is macguyver style bro. good on ya, that is over my head, but i see what you mean now.

 

[SternWake]

I did watch a lot of Macguyver as a child in the 80's. Part blessing, part curse. Retasking everything has its uses, but can lead to junk collection.

Best o luck with the new PCM.

On the middle socket in photo above, on the right side at about 3:30, you can see the edge of one of the springy Pin claspers meant to firmly grab the pin. Its tin plating has worn off and one can see the brass. These are not rated for many connection disconnection/recconection cycles. less than 10 before these claspers are bent out of the way not doing their job and one is 'hoping' the pin/socket is touching firmly elsewhere inside the connection.

Magnification, strong light and a sewing needle is all it takes to rebend these arms inward a smidge, to ensure a better connection on the first reseating of the connector. Doing so will give the connector the best possible chance of not failing or causing a similar failure mode which likely contributed to your current pcm failure.

 

[drewker]

I did watch a lot of Macguyver as a child in the 80's.  Part blessing, part curse.  Retasking everything has its uses, but can lead to junk collection.

Best o luck with the new PCM.  

On the middle socket in photo  above, on the right side at about 3:30, you can see the edge of one of the springy Pin claspers meant to firmly grab the pin. Its tin plating has worn off and one can see the brass. These are not rated for many connection disconnection/recconection cycles.  less than 10 before these claspers are bent out of the way not doing their job and one is 'hoping' the pin/socket is touching firmly elsewhere inside the connection.

Magnification, strong light and a sewing needle is all it takes to rebend these arms inward a smidge, to ensure a better connection on the first reseating of the connector.  Doing so will give the connector the best possible chance of not failing or causing a similar failure mode which likely contributed to your current pcm failure.

just ordered a used pcm off ebay that is apparently in good shape. it has a 30 day money back return policy so that is good, and it is the exact part i need, not refurbished or a different part number. it is supposed to be here tomorrow before 3pm usps express mail. they are going to ship it to the closest post office about five miles down the road. i called the post office first, they said it was no problem to ship to them, just mark "general delivery" on the package, and then show your id when it arrives. i called everybody this morning - lkq, junkyards, etc. nobody has the part i need on the west coast, all would require shipping and various times of shipping and costs so i am satisfied with the ebay seller, who has stellar reviews: 

http://www.ebay.com/itm/322024441643

if this doesn't work then i'm gonna start selling this van's parts on ebay myself... but i think it will work and big bertha will go another 100k miles...

 

[drewker]

I did watch a lot of Macguyver as a child in the 80's.  Part blessing, part curse.  Retasking everything has its uses, but can lead to junk collection.

Best o luck with the new PCM.  

On the middle socket in photo  above, on the right side at about 3:30, you can see the edge of one of the springy Pin claspers meant to firmly grab the pin. Its tin plating has worn off and one can see the brass. These are not rated for many connection disconnection/recconection cycles.  less than 10 before these claspers are bent out of the way not doing their job and one is 'hoping' the pin/socket is touching firmly elsewhere inside the connection.

Magnification, strong light and a sewing needle is all it takes to rebend these arms inward a smidge, to ensure a better connection on the first reseating of the connector.  Doing so will give the connector the best possible chance of not failing or causing a similar failure mode which likely contributed to your current pcm failure.

the only thing i don't know is if the pcm will be plug and play, or will it need to be formatted by the dealer, etc.

 

[SternWake]

On that year, I do not know either. Sorry.

Tyr Dodgetalk.com or dodgeforum on the B van subforums.

 

[drewker]

On that year, I do not know either.  Sorry.

Tyr Dodgetalk.com or dodgeforum on the B van subforums.

its a done deal either way now... all i need it to do right now is get me back to the bay area. worst case i can just take public transit and stay at airbnb rentals

 

[drewker]

its a done deal either way now... all i need it to do right now is get me back to the bay area. worst case i can just take public transit and stay at airbnb rentals

fyi i talked with that dodge mechanic i've been working with from justanswer.com - he said if the part number is an exact match, it should fire right up. no flashing it or taking it to the dealer.

 

[SternWake]

Glad to hear a new PCM got you mobile again, sorry to hear the hesitation issues remain. Perhaps you can explain better when and where the hesitation happens and describe the conditions of 'hesitation' better.

I sent the link of your ECM photos to my electronic's tech friend about the discolored potting. The link did not work for him, but I downloaded the photo of the burnt looking potting, and uploaded it to photobucket which does not allow as high a resolution when magnified.

But here is his response:

I have to agree absolutely that the pattern of discoloration is *very* strange... The components which should be generating the most heat are those black plastic squares with the 3 leads on one side and a little flange on the opposite side - they're either power transistors or MOSFETs. The heat doesn't at all appear to be localized like that... its diffuse nature is most odd.

I can't resolve any such large component component near ground zero, which to me appears to be along the heavy trace from connector lead #10, but something sure made that area most unhappy!

I wonder if there's something mounted to the opposite side of the board, like a massive top hat transistor or heatsink?

Something like that would lead to a more diffuse heating. Those power transistors typically are rated for 50-100 watts apiece; plenty to lead to charring of epoxy.


I totally agree with your assessment of the condition of the connectors surface mount leads. They're not in crystal clear focus, but in what I can see there is a definite narrow line of excessively light color running across each lead, along the bond line, which is out of place, and which would be entirely typical of the crystallized solder of solder fractures.

Solder fractures like that cause the signals to be subjected to intermittent higher resistance or even total signal dropouts, which can create all manner of havoc, from loss of control of an external circuit to loss of a sensor input to the module, to oscillation of a circuit. Oscillation causes a circuit to switch rapidly from ground to full power supply rails, which can lead to nonsensical symptoms and violent uncontrolled heating.

Even lead #8 isn't stellar in quality, and it appears to connect to a resistor across leads #6 and #8, which is likely used as a load for an external circuit which determines the presence of this plug in module, perhaps by coding a different value of resistor depending on the revision of the module. This could alter the system performance, like for instance 6 cylinder versus 8 cylinder, 360 vs 318, high altitude versus sea level, 117 amp alternator versus 100 amp alternator, California emissions versus the rest of the universe, etc...


I'm surprised that the heated area doesn't include the entire length of one of the heavy traces, or the 0.5 ohm sense resistor on the left; that small value resistor is typical of a shunt resistor used in a high current circuit... Rather than use a large solid metal shunt like we do in our high current cable circuits, most on-board electronic circuits just sense the voltage developed across a tiny value resistor like that.

I wonder if resoldering those connector leads would improve his situation? There's a lot of mischief which can be going on when so many leads are involved, especially when two of them are the heavy traces indicative of high current circuits...

I hope the new ECM doesn't bankrupt him, and that it works properly.


Did you determine if the chassis ground is essential to ECM function, as it is on my vintage of ECU module, being the essential electrical ground? If it is, please drive home to him the importance of scrupulously cleaning that area around the bolt holes, on both the firewall and on the new ECM, and of perhaps smearing some Silicon dielectric grease, antisieze compound, or at least some grease on the area to reduce moisture and Oxygen attack.

If it is a ground, those use a special bolt, which has teeth under its flange head; a regular bolt won't dig into the metal as well and concentrates its force in a smaller area around the hole. A large star washer can cure that issue if the wrong type of bolt (with a plain flat surface under its head) has been used.

I've learned heaps from this guy, but often his tech speak goes well over my head, like I am told my 'battery speak ' does to others.

Sorry i was busy yesterday when you texted and could not talk.

 

[drewker]

Glad to hear a new PCM got you mobile again, sorry to hear the hesitation issues remain.  Perhaps you can explain better when and where the hesitation happens and describe the conditions of 'hesitation' better.

I sent the link of your ECM photos to my electronic's tech friend about the discolored potting.  The link did not work for him, but I downloaded the photo of the burnt looking potting, and uploaded it to photobucket which does not allow as high a resolution when magnified.

But here is his response:


I've learned heaps from this guy, but often his tech speak goes well over my head, like I am told my 'battery speak ' does to others.

Sorry i was busy yesterday when you texted and could not talk.

no worries. the sequence has been.... the hesitations come first, then the other bad shit starts happening. i made it about five miles yesterday and decided to park it and gather more strategy. i have the grounding diagrams for my exact vehicle, but i cannot make any sense of them. i can check the grounding on the firewall and near the battery though. i was talking to an electrician i met yesterday at starbucks near santa cruz about this - he suggested something very obvious that i did not think of - in addition to zip tying the harness area, also zip tie the bulk of wires beneath the harness to prevent jostling. he thought my loose connector issue could definitely fry the motherboard. 

on a lighter note, i read bob wells article last night about the 2 million year old man - very enlightening! 

do you happen to know how mountainous / congested hwy 1 is to san fran from santa cruz? gonna try to reach my interview again which is thursday, have not decided which way to go yet. read there are lots of good spots for boondocking along the way

 

[drewker]

Glad to hear a new PCM got you mobile again, sorry to hear the hesitation issues remain.  Perhaps you can explain better when and where the hesitation happens and describe the conditions of 'hesitation' better.

I sent the link of your ECM photos to my electronic's tech friend about the discolored potting.  The link did not work for him, but I downloaded the photo of the burnt looking potting, and uploaded it to photobucket which does not allow as high a resolution when magnified.

But here is his response:


I've learned heaps from this guy, but often his tech speak goes well over my head, like I am told my 'battery speak ' does to others.

Sorry i was busy yesterday when you texted and could not talk.

drove from the coast to fremont with no hesitations or ce light. strapping that bundle of wires under the harness may have really helped. i can't declare victory yet though, been let down way too many times, but i'm thankful for some kind of hope.

 

[drewker]

UPDATE: in case anyone is curious, the computer replacement fixed the problem. i still have a few issues that are a concern, but the concerns i had initially with this post have been put to bed... i have logged a ton a miles since this happened doing various tech jobs in the west/northwest. got a used dodge van comp on ebay for around $200, paid for overnight shipping. fyi it was not the exact model number of the original computer, but it did not matter in the end. the culprit as to why the initial comp failed was a very small latch had broken off on one the computer connectors. basically it fried the motherboard by too much jostling over a long period of time. the latch is still broken, but i've got several zip ties holding it securely in place now.

 

[Every Road Leads Home]

Good news! Nothing better than hopping in a vehicle every morning and not having to worry about whether it will get you from point A to B. Even more satisfying when you finally figure out and fix the issue that's been harassing you.

 

[SternWake]

Good to hear indeed.  I was wondering what happened.

Thanks for update.

Those with Dodge vans from 88 to 2003 really need to be aware of this possible issue.

Too often it is the last thing addressed when it should be the first, or even better,  addressed before it can become an issue.

Take the weight of the wire bundles off the computer connectors, and make sure the electrical contacts within ECM connectors are not oxidized, and that the wires where they enter the connectors have not been backprobed, compromising the wire insulation.

I'd have saved many a headache, and have launched less tools into low earth orbit followed by a fury of curses, if I knew then what I know now.

 

[Goshawk]

Electronic issues happen a good portion of the time with vehicles now. My Toyota needs to have a good battery, not only to start, but also because the computer will do weird things if the voltage is low.


Sent from my iPhone using Tapatalk

 

[drewker]

Good to hear indeed.  I was wondering what happened.

Thanks for update.

Those with Dodge vans from 88 to 2003 really need to be aware of this possible issue.

Too often it is the last thing addressed when it should be the first, or even better,  addressed before it can become an issue.

Take the weight of the wire bundles off the computer connectors, and make sure the electrical contacts within ECM connectors are not oxidized, and that the wires where they enter the connectors have not been backprobed, compromising the wire insulation.

I'd have saved many a headache, and have launched less tools into low earth orbit followed by a fury of curses, if I knew then what I know now.

Indeed...and for anyone who may read this post, the van computer replacement model number was off by a couple of numbers from the original model number. I was worried about this at first but it fired right up when I installed it, and I have not looked back. You might have a seriously hard time getting a computer replacement for an older van that has the exact model number of the original computer. In fact nobody on the west coast had it, and the only one I could find was in Chicago at a salvage yard, and even that was off by a couple of digits.