no bus and breaking down in '99 Durango

[Cybrjaz]

OK - now I'm ticked . . . see post above for issues . . . replaced plugs, wires, cap, and rotor . . . replaced Camshaft Position Sensor . . . replaced Crackshaft Position Sensor (again - what a pain in the butt!!!) . . . checked battery, connections, and Alternator . . . replaced PCM . . . total cost around $425.00 . . . STILL HAS SAME PROBLEM!!!!

Will someone please tell me what to do next???

Besides blow it the ____ up!!!!

[Cybrjaz]

OK People - Listen Up - FINALLY got the stupid Durango running - please make a note and DO NOT REPEAT MY MISTAKES.

First off - the ONLY thing wrong with my truck was the CAMSHAFT POSITION SENSOR.

All of the other parts - Crankshaft Position Sensor, PCM, etc., were not necessary replacements . . . why???

Because what no one tells you is that if you replace EITHER the Camshaft Position Sensor OR the Crankshaft Position Sensor then you have to reset your PCM to FACTORY DEFAULTS and RELEARN the PCM to your particular vehicle's setup. The Camshaft PS and the Crankshaft PS are out of sync when you replace one or the other and when that happens the PCM will TEMPORARILY reset it's self to factory defaults but then revert to the previous settings thereby causing the vehicle to act all retarded again.

A few side notes - 1) Don't ask me how to reset the computer because I have no idea. I bought a new one and that didn't work either and I guess that SHOULD'VE already been reset - but whatever. I had a local mechanic look at it after I was at my complete wits end and wanted to use the stupid truck for AR-15 target practice. 2) The Crankshaft Position Sensor either WORKS or it DOESN'T. There is no "in between" or "intermittent" fault with this sensor. If you have an intermittent problem the Crankshaft Position Sensor is not the problem. 3) NEVER, NEVER, NEVER, EVER . . . move the Distributor. Apparently these stupid things are lined up just so and if you move them the Camshaft Position Sensor won't work right - stupid, I know. 4) Once you reset the PCM to factory - it will run crappy - not crappy as in not working but crappy as in a little higher RPM and a little lower MPG. This will level off as the vehicle relearns it's self and settles down - usually within 50 to 100 miles.

I REALLY REALLY REALLY hope this helps someone else because - Lord knows, I could've used this info 3 weeks and $450.00 ago. Thanks for all those that did help and I'm sure I'll be back.

[cowboy4570]

one thing to check is the ground wires next to the ac comp. looking under the hood left of the ac comp. 2 black wires one connector small wire not making connection would now start unless code reader was hooked up untill i hooked the ground back up still have the no bus and the idle air control system code still checking into it

[Mohawk55a]

In my case you are exactly right with your description of the problem. My 2000 Durango was having this problem two years ago. After replacing the PCM we disassembled the old one, scraped out all the muck, and examined the connector pins under a magnifier. Sloppy soldering... ring cracks existed around several of the pins with one almost completely around the middle 5v pin that others here have traced the problem to. Probably the heat caused the board to warp and break contact at the crack.

Originally Posted by Benzman

The problem is actually where the connectors solder to the circuit board. And yes, I attempted repairing and just wound up destroying the surface mount components on the board. The problem is that they fill the entire module with muck that is impossible to remove.
You'll have to replace the entire module. Look at my previous post, there are some modifications you can do to keep the module running cooler.

[chairborneranger1]

i have a 1999 dodge durango and the check engine light went on. the odtemter stop working and when i hooked it up to the tester it told me that the vehicle speed sensor wasn't working. so i replaced the sensor and the promblem are still there so what could be the promblem and also how do I reset the vehicles computer?

[mzdeal]

I'm betting Mohawk55a has found the most common root cause. Another blogger engineer reported it was an internal manufacturing defect. All the other bloggers seem to be guessing (here and everywhere).

My "no bus" problem appeared 8/07 less than a month after I installed shorty headers and a 180 T-stat, both of which help to heat up the engine compartment. Problem appears when hot and is affected by wiggling connectors.

I didn't fix mine, since I wasn't sure what to spend precious $ on. I did waste time though re-soldering all my connector females. So I rigged a forced air cooling fan/duct/enclosure for the PCM; bathing it in outside ambient air. This did the trick, except when I stop the engine the fan stops and the PCM starts heating up from residual heat. If I soon again start up, then I might see the problem appear.

Question for Mohawk: Do you think I could re-solder my pins without undue trouble, and get the PCM back up? Would I have to pull the board out of the case? Or could I do the job from the front? I'd like to fix this darn problem once and for all, but I surely am not gonna buy a new computer because of a stupid lousy solder joint!

[Mohawk55a]

mzdeal,

The problem would be getting through the potting goo that they fill the inside of the PCM case with. If you or someone else knows an effective way of removing enough of that to work with, it should be no problem. We found the goo to be very stubborn and frustrating... since I already purchased and installed a refurbished PCM myself, I wrote off the old one and dug out the board without regard for putting it back together again. I don't think I have the patience to consider it "undue trouble".

Originally Posted by mzdeal

I'm betting Mohawk55a has found the most common root cause. Another blogger engineer reported it was an internal manufacturing defect. All the other bloggers seem to be guessing (here and everywhere).

My "no bus" problem appeared 8/07 less than a month after I installed shorty headers and a 180 T-stat, both of which help to heat up the engine compartment. Problem appears when hot and is affected by wiggling connectors.

I didn't fix mine, since I wasn't sure what to spend precious $ on. I did waste time though re-soldering all my connector females. So I rigged a forced air cooling fan/duct/enclosure for the PCM; bathing it in outside ambient air. This did the trick, except when I stop the engine the fan stops and the PCM starts heating up from residual heat. If I soon again start up, then I might see the problem appear.

Question for Mohawk: Do you think I could re-solder my pins without undue trouble, and get the PCM back up? Would I have to pull the board out of the case? Or could I do the job from the front? I'd like to fix this darn problem once and for all, but I surely am not gonna buy a new computer because of a stupid lousy solder joint!

[mzdeal]

I suppose its worth another look. I pulled the case apart once before, but went no further once I saw that goop. If you can remember, are the pins soldered on the "top side" (cover side) or the "back side" (toward the cast casing)?

It would be a lot easier if I don't have to pull the whole board out of the goop. If I could just dig out enough goop from the front to get in there and work the joints, that would be well worth a morning try.

Pulling the whole thing out to get to the back seems like trouble. Might be easier just to cut an access whole out of the back, if possible.

In my case, I'll have to be careful so as not to damage anything.

Milt

[sheltonclan]

ARGH! Our 2000 Durango is experiencing the same lug/surge, stalling issues I am reading about here. Additionally, it will stall as I am driving along - last night at 45 mph. The code said it was the cam sensor - which we replaced, and today it still was acting up, code said the crank sensor - so we are replacing that too. BUT...we just replaced these parts about four months ago. AND, we replaced them about a year ago.

What would make the cam &/or crankshaft sensors fail repeatedly?
Thoughts? I am out of money and feeling pretty hopeless - with 16 months left to pay on this thing. Sigh.

[mzdeal]

I can't comment on those sensors except to say that you should be able to "test" them to see if they are working properly. It is unlikely that these devices actually have failed repeatedly.

As the weather warms up this problem is resurfacing ("no bus" shutdown) in my '99. I have cool air blowing on my PCM, so when it stalled today at a light I just popped the hood, wiggled the the middle connector till I heard the automatic shutdown relay click (other side of engine) and it started right up.

If your problem is the same, you should see a "no bus" in your odometer screen. It usually happens when it gets hot, and results from an intermittent connection problem at the PCM and the middle harness connection. Also the gauges all shut down. Cool down or wiggling this connector usually restores normal function.

If you're electro-mechanically inclined I'd recommend some trouble-shooting before buying parts. In my case it seems I'll need to resolder the PCM circuit board connector pins, which will be a hassle. Or, I can get a "rebuilt" PCM off e-bay (in Florida) for under $200 flashed.

Check all your connections.

Milt

[jpink]

im also having the no bus problem i have been disconecting my battery for a minute or so and then it rerstarts fine i hate the thought of buying a pcm