no bus and breaking down in '99 Durango

[1tufmama]

I have a 99 Durango 5.9L, 105k with the same problem.

Is the Power Control Module the same thing as the Powertrain Control Module?

To file a complaint go to:
http://www-odi.nhtsa.dot.gov/ivoq/

We broke down several times with the same problem on our 99 Durango after going 150 miles into our vacation. It was crazy trying to get off the freeway, no steering/brakes and an 18wheeler bearing down on us! Needless to say we had to come home, but at least we made it home safely. I certainly don't want others to be in the situation we had to endure.

Well, I just found out that if the car is over 8 years old, they are not required to do a recall...bummer!

[wylieSteve]

Originally Posted by 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.

After a longer drive, discovered that this provided no joy, the car still died. Bought a Crank position sensor and finally got installed. Drove the vehicle about 2 hours, and the problem happened again. So, still no joy.

Spent the weekend following carefully the diagnostics for each of the sensors on the 5 volt bus, but none are shorting, and I can't find a short in the wiring either. I cleaned the contacts on the PCM connector pins for the 5 volt bus (pins 4 and 17) with DeoxIT and now I can cause the problem when the vehicle is hot by wiggling the PCM connector. The problem still never happens when the vehicle is cold.

I've ordered another product from CAIG called DeoxIT Shield that is a contact enhancer. Conceptually I think it's similar to the NoAlox mentioned in a previous post. When it arrives and I get it put in, I'll follow up again.

[1tufmama]

We tried a product similar to NoAlox from I.C.E. that is a conductive anti-oxidant with aluminum filings. It didn't help. Haven't tried switching out the pcm yet...I guess they don't make new ones anymore, just the reman's according to the dealership. Also, heat/warping could still cause problems on your replacement part in the future.

To temporarily fix the problem until our pcm part arrives, we re-routed the windshield washer fluid over the pcm with small holes to spray fluid on the pcm while driving to cool it down. I know it sounds redneck but we drove it for 500 miles roundtrip without an incident here in Arizona where the temps can be brutal. We are still replacing the pcm and considering installing a fan or air vent to help control the problem in the future.

Thanks for the info everyone and keeping us posted!

[wylieSteve]

After my last post and the extensive diagnostics of everything on the 5v bus as mprtech and shango recommend, I was still having the problem, but none of the sensors on the bus tested bad.

I took it in to my regular mechanic, who put it on their diagnostic machine and said they didn't have sophisticated enough diagnostics to determine what was wrong, told me I'd have to take it to Dodge.

Took it to McKinney Dodge who spent several days trying to diagnose the problem and then reported that the central timer module was bad. I let them replace it. They called me after they had replaced it and told me that the vehicle still died, but the "no bus" message was fixed. Skeptical, I went to the dealer and showed them that the "no bus" message still appeared when the vehicle died, and they agreed to replace my original central timer module ($500 part).

They did a bunch more diagnostics, including repairing one of the PCM connections. I had removed the connector so many times that the locking tabs had broken off. The tech replaced the connector and re-taped everything - really looks nice. After 2 more days of diagnostics costing $340, they came back and said the PCM was bad. I told them I had already replaced the PCM and was skeptical of that diagnosis. I asked if they would put on a PCM but remove it if it did not solve the problem. The answer was no. After some haggling, they were really convinced that it was the PCM.

I sent the PCM with the results of Dodge's diagnostics back to the folks I got the refurbished PCM from, and they cheerfully replaced it with another refurbished PCM. This PCM solved the problem. We drove the vehicle Labor Day weekend on about a 5 hour trip to Arkansas fully loaded with kids, dogs, bikes and cartop carrier with no problem. We've driven it around town a lot with no problem, and over the weekend I pulled the horse trailer about 45 miles round trip with no problem.

Before it was fixed, the problem became very easy to replicate. The vehicle would die if idled in the driveway for 15 minutes or so with the A/C on high. Anything that causes underhood temperatures to climb, but I never saw the engine temperature climb over 210 so it's not really an overheating problem.

After reviewing the wiring diagrams on alldata and the diagnostic information available on other websites for how to test the sensors, I believe this problem could be caused by any of the sensors on the 5v bus (crank, cam, throttle, MAP, trans), the wiring or the computer. There does seem to be a problem with the computer, probably with a circuit trace pulling away from the board when it gets hot. In my case, it was the PCM, but might be something simpler and cheaper, you just have to check them all.

Hope this helps someone. I'm glad to have my 'rango back, we were without it all of June, July and August.

[nkmn]

after reading many posts, we went to our mechanic and had him replace the pcm because our 99 started stalling too with nobus in odometer. PCM replaced...... have had no problems in several months. Dont go through all the other sensor replacemnts and such that they suggest it could be.... pcm should be your fix. If you have any questions let me know.... neilandkari@msn.com

[socaldriver]

I have had this same problem for a month. I took it to my local mechanic twice, and he said there were no codes in the computer and he could not diagnose it. I then took it to the dealer, who claimed there was a code in the computer for a faulty IAC. They changed it to the tune of $409.

As you know from prior posts, that was NOT the problem and the car still stalled and showed "No Bus" in the odometer. I took it back to the dealer, who could not re-create the problem and could not diagnose it. I then Googled the symptoms and several websites came up indicating this problem. Taking all of your good peoples' advice, I ordered the PCM through Auto Comptuer Exchange, changed it out and -- car works fine.

I went back to the dealer to get my money back, but they refused and claimed this is not a common problem, that they never heard of it and that "the internet is not a diagnostic tool" (I love that one -- seemed to work pretty well for me).

Anyway, I'll still pursue them, but all's well that end's well. It is the PCM. You can change it out yourself with minmal time. Entire cost was $314. Thank you for all the comments and especially the follow ups which set us straight.

[cruzsalinas]

Hi. I have the same problem. I like to know if you check over heat in your previous PCM and if the new PCM does not heat. Regards

[socaldriver]

Cruzsalinas: I have not had a repeat of the problem since changing out the PCM. However, I have not checked on whether the new PCM overheats. I am going to guess that, over time, this problem will repeat as the heat begins to warp the motherboard in the PCM, but that is just a guess. Others on this board and elsewhere have stated that the problem is heat and subsequent warping of the motherboard, but I can't verify that and I don't know of a way to verify it. We'll have to see. My Durango has about 105,000 miles on it and I just want it to get to 150,000 before I get a new car. I'll post if I have a problem, but the car is running great now. Thanks for your question.

[Benzman]

I made a few modification to the vehicle to allow fresh airflow over the PCM, rather than hot air in the engine compartment cooling the PCM.
It's really fairly simple:
Cut a hole in the plastic that is located behind the grill and next to the passenger side headlight. This now lets cool air into the area between the engine compartment and outside fender wall.
I installed a screen from an old screen door to keep the bugs and rocks out. Then, I installed a home-made duct out of thin sheetmetal to move the fresh air onto the PCM.
If you look at the body there is an opening near the PCM, so if you build a small duct to feed the fresh air to the PCM.
So, the fresh air enters through the screen, along the body (between the engine compartment and fender) exits through the opening into the duct.

At one time I had a fan in the duct, but didn't feel that it made much difference. Simply allowing the motion of the vehichle propel the air onto the PCM.

[hardheadfamily]

I have a 99 Durango 5.9 and the PCM was replaced less than a year ago with a reman. and it started to die again. I can move the wires on the middle connector and then the gas guage will work and I can here the relays click then it will start and run for a little while then die again.
Has anybody tried to puill the middle connector apart and adjust the female end of the connectore(i.e. smash them a little)?

[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.

[dmburrows]

If you purchased the reman from chrysler, it should still be under warranty. If not from Chrysler, it might be worth checking with the company to see what warranty is.

[Fodus]

I have a 200o Dodge Durango that had the same problem, it would stall and then say "No Bus" on the odometer. It did it a couple of times, and then not once over the Winter. Once it started warming up outside it happened all the time. I tried replacing the Crank Shaft Sensor, as this in one possible fix, but it did not fix the problem. In the mean time, I decided, that because it didn't ever happen during the Winter I would pack a bag of ice around the computer to keep it cool, and it worked! I would buy a bag of ice from a gas station, open it and pour some ice out right around the computer (the bag won't fit or let the hood shut if it is full), then I would reseal the bag, and pack it in around the computer itself. This temporarily fixed my problem, however I knew that it wasn't a final fix so I called the dealership for the price of a new computer. They quoted we just under $600 for the part, and $85 dollars for labor. I didn't have a spare $685 dollars so I called AutoZone. They charged me $276 plus a $65 core fee (which I got back when i returned the old computer of course). I took the thing home and put it in myself. It was the easiest fix I have ever done on a car and I am not a mechanic. It literally took me about 5 minutes to disconnect the battery, removed the 3 bolts that hold the computer in place, disconnect the 3 electrical connections on the computer, and then do the same thing in reverse. If you aren't sure it's the computer, try the "ice fix" and see if it helps. If that does it, DON'T go to a dealership and pay the high price unless you can afford it. Order if from AutoZone. They will ask you for the VIN, the milage, and a few other things. They have to order it over the phone, and give the company they call the info you supplied, and download all the info for your vehicle to the new computer. It is then delivered to AutoZone via Fedex in about 2 days.

[Cybrjaz]

OK - I guess after reading 5 years worth of essentially the same issue - I'm going to add my own dilemma.

My Wife has a 99 Durango 5.9L 4X4 with 175,000 miles. About a year or so ago it started jerking around when you tried to keep the vehicle running at a steady 50 MPH - At times it would almost seem like the motor was going to rip itself out. Accelerate to over 60 MPH and no problems - let off the gas and no problems. We took it to several shops AND dealerships and NO ONE could give us a straight answer (ranged from everything from transmission to the vehicle computer). Anyway - Wife said forget about it she would deal with it until something else happens.

Flash forward to about three weeks ago. She calls me up and says her check engine light is on and the truck sounds like its missing (yes - I am blessed with one of those rare Wives who ACTUALLY KNOWS something about vehicles). No problem - I get home - hook up my handheld scanner and it reads a misfire in cylinder #7. So, I figure its as good a time as any to go ahead and do a tune-up. New plugs, new wires, new cap & rotor. Replaced everything and I'm feeling pretty good . . . UNTIL I start it up after the tune-up - It sounding 100 times worse than BEFORE I tuned it up. I hook up the handheld and now I'm getting multiple misfires and a "P1391 (M) Intermittent Loss Of CMP Or CKP Loss of the cam position sensor or crank position sensor has occurred" error code.

I recheck everything and use the scanner to reset all of the trouble codes on the truck. Next thing you know - everything is running fine and there are no error codes registered.

Next day my Wife drives the truck and calls me later in the day and says it stalled at a stop sign but fired right back up and is driving fine. OK - maybe a fluke but then it happens again the next day and the Check Engine light comes on. So, I hookup the handheld again and this time I only read the 1391 error code.

So I do a little checking and figure the easiest place to start is the Camshaft position sensor and so I get a new one and hook it up. NO CHANGE IN CONDITION. So I then (agonizingly) change the Crankshaft position sensor (again - what a complete pain in the ass to change that thing) and start it up - clear the codes - recheck and all is well. I walk into the house and tell my Wife all is done and she goes down to the truck and starts it up and it sounds horrible. By this time the truck is revving erratically and stalling out in park.

So now I'm searching the forums and DUH!!! - I forgot to disconnect the negative thereby resetting the vehicle computer. So next day - do out and disconnect the battery . . . for an HOUR!!. Hook it back up - start it up - and ALL IS WELL!! I now have to buy new clips for the inner fender well (which you have to take off along with the passenger side tire to change the Crankshaft position sensor in all of about 3 inches of space between the back of the block and the firewall - again - real pain in the ass) so I drive to the parts store (about 5 miles away) and it stalls right in the parking lot.

By now - I'm pretty ticked off (except for the fact that up until that point the two fixes cured the initial problem at 50 MPH) - I go in and buy the clips and limp the vehicle back to the house where it sits in the driveway right now.

I've gone through multiple forums and I'm now at my wits end. I have all of the same symptoms as everyone else WITH THE EXCEPTION of the NO BUS code . . . I DO NOT have that issue. So I'm left with changing out the vehicle computer . . . I Think?!

3 Questions:

1) Lots of talk about PCM and ECU are these the SAME thing?

2) It has been suggested that if you replace the ECU (nothing about the PCM - if they are the same then that is strange) then you should also replace the IAC - is this true or am I just giving away more money?

3) Does the fact that I am NOT getting the "No Bus" signal indicate that I have a different problem?

Thank you for your time and patience and ANY advice will be extremely appreciated. I can be contacted at rick@mttlaw.com

Thanks,
Rick

[Benzman]

PCM and ECU refer to the same thing. But I think the proper term is PCM for these chassis dodges.
I don't know why you would need to replace the IAC (Idle air control unit) when replacing the PCM. I didn't, no problem.
The no bus is one symptom of the failing PCM. But it can also show up with stalling / missing. The PCM can also cause the security system to engage, which shuts down the fuel delivery, and ignition.

One thing to consider, a low battery can cause strange fuel delivery problems with these vehicles, because the if the voltage that is fed to the PCM is low, the PCM acts up.

So, I would recommend taking the vehichle somewhere that they can check out the battery and alternator under loaded conditions. AutoZone, Pep Boys, Checker all do it for free.

If the battery and alternator are OK, then consider replacing the PCM.