no bus and breaking down in '99 Durango

[dmburrows]

http://www.automotiveforums.com/vbul...d.php?t=406260

I finally broke down and paid the $800+ to have PCM replaced. That was definitely it. Not long after that water pump cracked so I had to buy pully tool to replace pump. Everything ok for now.

[Custnam]

I went ahead and bought a new/remnufactured one from ecu direct.com for $434 and it fixed it. But the trucks being repoed soon. So Ill be pulling the good one out and reinstalling the bad one. So anyone that wants to get rid of their "no bus" problem for good make me an offer and Ill let it go. My email is [email protected] Thanks

[mprtech]

The only post in this thread worth reading is the one by Shango. I've seen more shorted 5 volts causeing no bus than any other issue. Its easy to diagnose if its actually broken when testing. Next time you get a no bus message unplug your TPS and measure your 5 volt wire. If it shows 0 volts then check for continuity to ground. Most likely that is what you will find, a short to ground. Then its a matter of unplugging 5 volt sensors one at a time and seeing when and if the short goes away. When the short dissapears then thats the shorted sensor. If you unplug all your 5 volt sensor and still have a short to ground then you need to check the wiring. I have had one Durango that had a shorted wire on top of the trans near the connector for the trans solenoids.

[jbrj]

I had this exact problem for a couple of months where it would break down and I checked this website and they gave me some excellent advice.

For starters....if the durango dies, pull over, pop the hood, and wiggle the Power Control Module (pcm). Thats what worked for me. The part is available through NAPA for $289.00. But you have to find someone who knows what you are talking about. I live in Tillamook Oregon and I had to get the information from the Battle Ground Washington NAPA. Schucks and Carquest didn't even know the part existed, they told me my car didn't even have a pcm. Get a Haynes manual and look up how to take it out. It is so easy, it literally pops out. Then you will take it in to Napa and they will send it in to be rebuilt. Then when you get it back to make sure your grounded and pop it in.

I replaced mine about a month ago and I haven't had any problems since.

[Cvolpe]

I have a 99 Durango with 82K on it. Haven't had this problem but now that i've read up on it I'll be aware of it if the car suddenly dies on me. Thanks for the info.

As far as Dodge not caring, that is right on. I had this car for two months, brand new when the fuel pump died. The dealer couldn't get a pump for two weeks because apparently a lot of cars were having this problem and they didn't have enough pumps to go around. They wouldn't give me a loaner because I didn't get the extended warranty, like it was my fault they can't stock a problem part. I even called their headquarters and they told me tough luck. That is why I won't buy another dodge although this one has served me well. They can't even spell customer service, let alone practice it.

[Steve98055]

Originally Posted by jbrj

I had this exact problem for a couple of months where it would break down and I checked this website and they gave me some excellent advice.

For starters....if the durango dies, pull over, pop the hood, and wiggle the Power Control Module (pcm). Thats what worked for me. The part is available through NAPA for $289.00. But you have to find someone who knows what you are talking about. I live in Tillamook Oregon and I had to get the information from the Battle Ground Washington NAPA. Schucks and Carquest didn't even know the part existed, they told me my car didn't even have a pcm. Get a Haynes manual and look up how to take it out. It is so easy, it literally pops out. Then you will take it in to Napa and they will send it in to be rebuilt. Then when you get it back to make sure your grounded and pop it in.

I replaced mine about a month ago and I haven't had any problems since.

I fixed mine, and am 100% certain what the problem was (at least on my '99 Durango).

I too had the same problem, and read everywhere about it being the crank sensor, idle air controller, ignition switch, as well as the horror stories of replacing the PCM etc and spending thousands of dollars and still having the problem.

I did replace the IAC and still had the problem, and was about to replace the crank sensor, but what didn't make sense is why would it stall, and then reset itself if the sensor was bad. I decided it must be the PCM and ordered a new PCM. A shipping screw up happened, and it didn't get shipped, so I cancelled the order and decided to take some time and diagnose the problem, and I'm glad I did. Read on..

The problem was stalling (usually after the engine is warm. Gauges all go to zero, sometimes it says NO BUS, and won't start for 5 to 20 minutes. Then it starts just fine.

What I did find out was that when I left the key on, and wiggled the middle wiring harness to the PCM I would hear a relay click, and the gauges would come up, and the engine would start first time. I also noticed that if I just opened the hood, and let some heat out, it would do the same thing.

Of course once it cooled and made a connection, I couldn't duplicate the problem again, and had to wait until the next time it died to narrow down the problem some more. (This could be entitled how I spent my summer I guess!). Anyway, in preparation for the next time I took the covers and tape wrap off of the middle harness, suspecting that it was a broken wire.

The next few times it happened I narrowed it down to one of five wires near the front of the middle harness. I could even wiggle the wire bundle at the connector and make it die a couple of times before it cooled down. So by this time I was 100% sure that the PCM was NOT the problem, but the wiring harness was. And I knew I could get it started again.

I tried to duplicate the problem in the driveway by heating the wires with a hair dryer, but couldn''t duplicate it. I removed the PCM and looked at all of the connections with a magnifying glass, and could see that they were all intact, no fractures showing (these are gold contacts). The interior of the PCM is gell filled, so the board is held pretty solid.

I checked on the price of a wiring harness from the dealer, sit down, $1180.00. That wasn't going to fly.

The next few times it happend, I narrowed the problem down to three wires, but realized that the problem was AT the connector, and not the wire. But when it stalled, I could wiggle the wires, and get it to start immediately, so I knew it wasn't the crank sensor or the PCM.

So I was 100% certain that the problem is a connection from the wiring harness to the PCM. The connectors in the harness are aluminum, connecting to a gold plated connector at the PCM. The problem is that heat/moisture etc causes a bad connection, or causes the female connector in the wiring harness to spring open slightly, and make a bad connection.

Cool it down, and you get a connection again. So now that I was sure of what the problem was, I had a choice of spending $1180 for a new wiring harness, building a new harness, replacing the connector, or figuring out a way to get a better connection.

Well the solution was simple. I use some of the Ideal NoAlox electrical joint compound in my boat trailer plug to get a good connection, and keep those connectors from corroding. You get this stuff at Home Depot and other places in the electrical department. It is a thick paste with aluminum filings in a grease, and is used for ensuring good electrical connections in your home power panel.

Anyway, to make a short story long, I removed the middle connector from the PCM, and put a SMALL drop of NoAlox in each of the female ends of the connector. Then I wiped off ALL of the excess so the only spot any of the NoAlox was showing was in each connector. You don't want to put too much and risk shorting any of the PCM pins.

Before adding the NoAlox I could tell when the engine was going to stall, or when it was at risk, because I could see the Tach drop a few hundred revs, then catch itself, and no it was getting close to happening again. After the NoAlox, it has NOT failed or stumbled, not even once!

[Durango1000]

Thank you Steve for all of your valuable research. I have to agree, you've hit the nail on the head. I too suffer from this lousy engineering issue. As you directed, wiggling the center wiring harness absolutely gets things going again. I just gave mine a little tug and heard things click back on again.

I would like to point out three things that may help others:
1) Where is the PCM? I had a hard time finding it. Basically, if you are standing in front of your durango looking under the hood, look above the left wheel well. There is a rectangular box looking thing with three wiring harnesses plugged into it. On mine, the center harness has a white cap, the other two have black caps. The center one seems to be the issue, as steve pointed out.
2) To get this off, don't remove the "cap" from the wiring harness plug, you have to remove the entire plug.
3) I tried the Nolux, but getting it into the holes isn't easy. The tube has a hole the size of a pencil, and the harness has holes the size of pencil lead. More specifically, the size of a jumbo paper clip. That's what I used to get the Nolux into the holes. I first tried dabbing just a little into each hole without pushing it down deep. I was hoping the pins would then get lightly coated when I plugged it back in. Didn't work. The car died again about a week later. I just now added more Nolux by dipping a jumbo paper clip into the goop, then pushing it down in each pin hole. Seems to be a perfect fit. (note, not every hold in the harness has an electrical connector behind it). you'll notice this if you use the paper clip, because some holes will just feel big and empty, while others obviously have the female half of the connector. Again, don't know if this will fix it this time. i'll post again if it once again dies.

Again, thanks to Steve for finally pinpointing the source of our woes. This is certainly a DANGEROUS issue as it just flat-out dies. Which means your wife could be going 45 mph down a windy mountain road and loose power steering, brakes, etc... Dodge should recall this immediately. Someone is going to get hurt.

[kkutah]

same problem, "no bus" durango 99...scanner says its the IDLE (code p0505)but my car wont start at all, so I think I need to replace the PCM or try to do what steve98055 and durango 1000 did!?!? hey steve98055 and durango 1000 is the car running good still?
Heres the thing...my car starts and no "no bus" message when a scanner (the ones used to tell you whats wrong)is plugged in!!!

[Durango1000]

Well, it didn't work. It broke down again. I even tried spraying contact cleaner into both the plug and the PCM pins, drying off with compressed air, and reconnecting. It still sporatically dies. If I reach under the hood and pull up on the center plug, it usually starts right up though. So, I am convinced that the problem lies with this area, but I'm beginning to think perhaps there is some kind of crack on the circuit board of the computer itself. this would explain to my why applying force on the plug may re-establish a connection, yet not be permenantly fixed by thoroughly cleaning the contacts. I don't know. I'm at a loss and very frustrated at Dodge. What's more frustrating, is that the local dodge dealership knows nothing about this issue, so of course they simply want to replace the computer and/or wiring harness. You'd think there would be some kind of "mechanics bulliten" that goes out to certified dealerships with troubleshooting tips when these things start popping up.

[kkutah]

Thanks Durango1000 and Im very frustrated 2, I see that everyone has this "no bus" and transmission problem. I had the trans rebuilt a year ago (over $2000) and now the 2 gear wont shift unless I take my foot off the gas. Replaced the coil ignition 2 months ago ($400), and the gas mileage killing me...especially cause Ive got offroad oversized tires and lift, it looks good only 80k now. Going back to the "no bus" problem, my car didnt even start anymore, untill it started with the scanner connected, so Ive been driving like that for about 3 weeks now, I am trying to find a computer at a junk yard, if dont find one I will go to the dealer, either way ..once fixed I will sell it.

[cstradling24]

I had this problem exactly a year and 2 months ago. My 1999 Durango had 180000 miles on it. I had the PCM replaced and the problem went away.....

But now I have a similar problem but quite the opposite. Now the car doesn't shut itself off, it wont turn on. I go to start it and you wont hear the fuel pump and there are no gauges, then the NO BUS will light up on the odometer. I am leaning towards the PCM again but I am not 100% positive. This is all just frustrating. The $700 I paid for the dealership to replace the PCM a year and 2 months ago is now down the drain and they only warranty the computer for one year.


BS, I will NEVER get a dodge again.

[wylieSteve]

My 99 Durango SLT 4x4 5.9l started having this problem about a month ago, but it's getting worse as it gets hotter here in Texas. Today it did it twice, the first time in heavy traffic while pulling la loaded horse trailer. It also seems to be taking longer to reset. After reading all the posts in this thread, I have several observations about my own case:
1) wiggling the PCM harness/cables makes absolutely no difference
2) the PCM case gets pretty hot
3) I've only seen the "no bus" message once out of the dozen or so times it's shut down.

I'm trying the approach of buying a refurbished PCM from http://www.autocomputerexchange.com since they'll reprogram it to my VIN and mileage. $314 with shipping. I'll reply back in a few months and give an update on my success or failure.

[wylieSteve]

Received the new brain from Auto Computer Exchange, 8 days after I ordered it. Re-installed it, went for drive, no problems on the 7 mile test drive.

[J_Utah]

I have a 99 Durango with pretty much the same symptoms everyone else was having. No Bus error. Sporadic shutdowns. 2-20 minute restart.

It is a nasty little problem to troubleshoot given its sporadic nature. Since time was short for me as I didn't want my kid's in an unsafe situation (eg, the car dies on the bridge with no shoulder) I figured I would try replacing the crankshaft sensor first because it was cheap and if that didn't work I would change the PCM. This was a risky approach because the problem could be something else and then I would be out $450. However, I talked to a GM Service Center and when I explained the systems the mechanic said without hesitation - "sounds like your pcm is bad".

I replaced the sensor and that didn't fix the problem. It is a bit of a pain getting at the sensor but it isnt too bad (I removed the front right inner wheel well). So, I ordered a PCM from ecudirect for $400 ($300 if you have the time to send in your current unit to be fixed) and it arrived a couple of days later. It is very easy to replace and even someone with little to no automotive experience can replace it (saves $400-$600 to do the 10 minute job yourself).

The new PCM fixed the problem and I haven't had a problem since.

[kkutah]

Thanks wylieSteve and keep us updated please.

Hey J utah are you in salt lake?