1999 Dodge RoadTrek PCM Issues

[ScienceMagic]

Sure hope someone has some good ideas!

I own a 1999 Dodge 190V that I bought new. Two years ago I got the dreaded "no bus" error in the odometer. After the dealership gave up, I suggested they put in a refurbished computer from Mopar. That seemed to solve the problem.

This summer I had an off-road shop weld on a new front end to replace the rusted out one, to the tune of 12K. They took the old computer off before they started the work. Did a good job, but after putting everything back, the van would not run, unless pin #5 on the OBDII port was shorted to ground.
This is the "signal" or "sensor" ground, according to my research. I was able to get the engine to run by jumpering the ground wire from the camshaft sensor to a known ground, but the jumper gets quite hot, so there must be a lot of current going through it.

The shop bought a computer from Auto Zone, then took the van to the dealership to have it flashed. The dealer has had it for almost a week, and can't seem to program the computer.

The van is 400 miles away, and I'm not sure what to do. It's driving me crazy, and I'm starting to lose sleep over it!

Anyone have an issue like this before? I'm thinking the old computer was not getting a good ground somehow (although I checked the wiring harness with a multi-meter and it seemed like it was good to ground), but why the dealer can't flash the new one is beyond me. They claim their technicians are young, and don't know how to do it!

 

[Stevemo-ClassB]

I think people use zip-ties to hold the connectors on to the PCM to resolve the no-bus issue.
I would have the shop go through the grounding on the van to see if they removed any. There will be a ground going down to the starter and onto the back of one of the cylinder heads. I don't recall where the body ground is.
A lot of garages will use a hired gun to program PCMs and other modules. There should be an expert in the area where the van is located that can go in and program the van in place. If not, have the van towed home before they start charging you rent for storing it.

 

[ScienceMagic]

One of the connectors is ALREADY held in place with a zip-tie. I guess I could put on zip-ties on the other two.
I looked for ground wires, and found one to the alternator and also to the body. Don't remember seeing one of the back of the cylinder heads, but I could easily have missed that.
Yeah, I'm going to have to drive to Ohio next week and have the van towed to a storage facility until I can figure out what to do with it.
I hate to give up, but not sure what else to do.

 

[Stevemo-ClassB]

Hopefully you can figure it out. Perhaps you could go find an entire harness and PCM out of another van with similar options to limp it home? Worst worst case you would need to install an aftermarket computer and gauges.

 

[ScienceMagic]

I've thought about the wiring harness. I know the part number for the engine harness, and can find used ones online. It comes with the transmission harness as well, but NOT the instrument cluster harness nor the body harness.
The Dodge parts guy said it was unlikely that the other two would cause my issues, but who knows. Maybe there is some light or switch in the body that has shorted and is causing the problem?

 

[rstl99]

Sure hope someone has some good ideas!

I own a 1999 Dodge 190V that I bought new. Two years ago I got the dreaded "no bus" error in the odometer.

This summer I had an off-road shop weld on a new front end to replace the rusted out one, to the tune of 12K.

The shop bought a computer from Auto Zone, then took the van to the dealership to have it flashed. The dealer has had it for almost a week, and can't seem to program the computer.

I don't have any good ideas, but being the recent owner of a 2001 Dodge Roadtrek 190P, your post gives me some concern.

1. New front end to replace the rusted one. Are you referring to the front cross-member? Wow $12,000... How did yours get that rusty? Did you drive it in the winter in the rust belt?

2. "no bus" error, computer issues, dealer unable to resolve. Those kind of electronic issues give me the heeby jeebies. How prone are these old Dodges to issues like this, which I understand can be very difficult to sort out (and with new parts no longer available from Chrysler)? Maybe I should have looked for an older Dodge Roadtrek, without as much electronic components inside...

Good luck with your issues.

 

[ScienceMagic]

Yeah, electrical issues are a pain, for sure!
I bought the van in Texas, but then moved to the Midwest. I drove it a lot in Chicago winters, and about ten years ago discovered that the front end was horribly rusted out. I did the best I could to clean it up, paint it with rust proofing paint, and replace many components, but the damage was already done.
The frame shop cut off the front end behind the spring perches, and welded on a frame from a Georgia van that had little rust on it. To do that, they had to pull the engine and trans.
My guess is when they put everything back together, they stretch some wiring harnesses, and that has led to this problem.
I have read that Dodge has had computer problems a lot, although the dealership told me two years ago that "they almost never fail," right before they put in a new one!
I don't mind electronically controlled engines, I just wish there was a way to find out which component has failed. The "no bus" message means communication has broken down, but it could be a lot of things: crankshaft position sensor, camshaft position sensor, MAP, or just a break in the wiring someplace.
On the plus side, I see a LOT of these era vans still driving around, especially in the South.
It's easy to lose sleep worrying about what can go wrong. Sometimes you just have to do your best to keep things in shape, and try not to imagine the worst!
I WOULD check under the front end of your '01, and make sure the frame horns are not rusting out. If you can, spray the inside with a rustproofing paint. I've used Eastwood Internal Frame Coating spray, with limited success. Some people recommend linseed oil, or there is another oil product that people use, that supposedly smells really bad, but works.
I just plan on not driving the van on salt roads, once I get it running!

 

[rstl99]

Hi ScienceMagic,
Well that's what I thought: winter-salt driving will kill most cars or trucks, so I can understand why you had to get done what you did. Pretty radical transplant surgery but I suppose you're very fond of your Roadtrek, it's served you well, and you figured it was worth fixing it up for another chapter of your life together. And you're probably right about wiring harness issues resulting from the major surgery and drivetrain disturbance.

First thing I do (up here in the Rust Belt) when I look at a used car is bend down and look underneath for rust. This particular RT I bought was almost rust-free, had evidently been rust-proofed over the years, which is what I do to my vehicles as well. We have a rust prevention treatment up here called Krown, they get the vehicle on a lift and shoot the oil all over the chassis and underneath nooks and crannies, frame rails if they're thorough. They also drill holes in the door frames and shoot oil inside the lower body cavities.

That, and not driving a vehicle in the winter and salt, will make it last almost as long as the Southern US trucks...

As far as electronics, yeah it's progress in mechanical engineering so what can we do? It's everywhere, and more and more so. Too bad the 20 year old Dodges are no longer supported with replacement parts (ECM and other such modules) but what can we do.

I like your attitude about not losing sleep over issues like that. I paid a very handsome sum for my Roadtrek, due to its very nice condition, so I'm a little sensitive to debilitating electronic problems at this point in my ownership. Vehicle transfer was delayed over a month because of a persistent "air bag" light issue in the dash that a persistent mechanic was finally able to get sorted out (thanks in part to a used module from Texas). So I suppose I've already had an electronic issue to deal with...

ANyway, thanks for explaining your issues, and I hope all gets sorted out for you sooner than later.

 

[ScienceMagic]

Well, I've put a TON of work into this van, so I don't want to just give up! Aside from the front end replacement, I also replaced the rear leaf springs myself, did a front end rebuild eight years ago, did a LOT of painting with Rust Bullet, rewired the interior lights, replaced the 3-way frig with a Nova Kool compressor model, wired up the electric water heater, and too many other small projects to name!

It has lots of annoying problems, but I'd like to keep it, at least until I decide to spend the money on a new camper van.

I've never heard of Krown. Sounds like you've had good success with it. Is it done every year? Does it collect dirt and sludge? That's what I'd be afraid of, that moisture would get trapped and cause more problems.

I've got a long list of things I want to try this week, when I drive the 400 miles to where the van is, including checking all (or most) of the circuits connected to the PCM for shorts.

If I were in your shoes, I'd buy a pre-programmed PCM as a spare, and make sure it runs the van, then carry it with you, just in case!

 

[akahomer1]

Sure hope someone has some good ideas!

I own a 1999 Dodge 190V that I bought new. Two years ago I got the dreaded "no bus" error in the odometer. After the dealership gave up, I suggested they put in a refurbished computer from Mopar. That seemed to solve the problem.

This summer I had an off-road shop weld on a new front end to replace the rusted out one, to the tune of 12K. They took the old computer off before they started the work. Did a good job, but after putting everything back, the van would not run, unless pin #5 on the OBDII port was shorted to ground.
This is the "signal" or "sensor" ground, according to my research. I was able to get the engine to run by jumpering the ground wire from the camshaft sensor to a known ground, but the jumper gets quite hot, so there must be a lot of current going through it.

The shop bought a computer from Auto Zone, then took the van to the dealership to have it flashed. The dealer has had it for almost a week, and can't seem to program the computer.

The van is 400 miles away, and I'm not sure what to do. It's driving me crazy, and I'm starting to lose sleep over it!

Anyone have an issue like this before? I'm thinking the old computer was not getting a good ground somehow (although I checked the wiring harness with a multi-meter and it seemed like it was good to ground), but why the dealer can't flash the new one is beyond me. They claim their technicians are young, and don't know how to do it!

do all the dodges have this going on with pcm how about chev or fords do they have pcm issues like the dodges??

 

[rstl99]

Well, I've put a TON of work into this van, so I don't want to just give up! Aside from the front end replacement, I also replaced the rear leaf springs myself, did a front end rebuild eight years ago, did a LOT of painting with Rust Bullet, rewired the interior lights, replaced the 3-way frig with a Nova Kool compressor model, wired up the electric water heater, and too many other small projects to name!

It has lots of annoying problems, but I'd like to keep it, at least until I decide to spend the money on a new camper van.

I've never heard of Krown. Sounds like you've had good success with it. Is it done every year? Does it collect dirt and sludge? That's what I'd be afraid of, that moisture would get trapped and cause more problems.

I've got a long list of things I want to try this week, when I drive the 400 miles to where the van is, including checking all (or most) of the circuits connected to the PCM for shorts.

If I were in your shoes, I'd buy a pre-programmed PCM as a spare, and make sure it runs the van, then carry it with you, just in case!

Thanks for the context. Yes, I can see you've invested a lot of time and resources in making your Roadtrek the way you want it, so can understand wanting to go the extra mile to keep it going.

Mine has been kept pretty well stock by the three PO's, so it's up to me to figure out what I'll want to do with it (solar or no, composting toilet, etc etc.). Maybe I'll just keep it stock until I figure out if my dog will take to it and allow lengthy road travels I've envisioned with it.

Here's the website of Krown Rust Control. I've been using them for years on many of my cars. They're available across Canada, and apparently in some places in the US. You typically apply it in the late Summer or Fall, and re-apply it every year. It's a sticky oil that is shot all over the underside and inside cavities. During winter the salt and snow and slush typically wash it off, so annual treatments are strongly suggested (about $125 each time). ANd no, it's not some fixed coating that can dry and crack and let moisture and salt get underneath and rot the car from the inside.

https://www.krown.com/en/

Yeah, sounds like a "pre-programmed ECM" may be a good thing to have on the road, along with a few other things. I have no idea where to source such a "pre-programmed" ECM, but will look into it.

THanks, and good luck.

 

[ScienceMagic]

do all the dodges have this going on with pcm how about chev or fords do they have pcm issues like the dodges??

I’m afraid I don’t know much about Chevrolets and Fords. It does seem that the Dodge vans from the early 90s to the early 2000s all have computers that have a tendency to fail, unfortunately. Also similar dodge vehicles, like the journey and jeeps. You can find a lot of stuff online about people with computer problems with these vehicles. Dodge also has this weird thing where the voltage regulator for the alternator is controlled by the computer, which is another computerized thing that can fail.
I have not heard much about other manufacturers who have these kind of computer problems, but they may exist. It makes me wonder if all the stalled cars I see along the expressways are actually cars who have had their computers fail!

 

[ScienceMagic]

Well, the problem was finally fixed! After driving to the dealership, two states away, I pulled the doghouse off and immediately saw where two ground wires were attached to a bolt, and that bolt was NOT tightened down!
I took it off, cleaned up the terminals and the place on the engine block that they touched, put them back on, swapped in the old, Mopar PCM, and it fired right up.
I'm still in shock by how EASY it was, and WHY two different shops failed to check for proper grounds.

After a test drive however, I discovered when they re-installed the engine, they routed the shift cable up against the exhaust header, which cased the cable, and two spark plug cables to melt. They are currently repairing THAT mistake.

I am hopeful it will be done this morning, and I can finally get this thing back on the road, after two months in the shop!

 

[rstl99]

Great to hear you sorted out the ground problem! Indeed all too often it seems, it's the simple cause that eludes troubleshooting, so it's good you spotted that loose ground. And sad about the lack of attention to the cables when reinstalling the engine, it seems the owner has to be very vigilant these days and not assume that "professional mechanics" have necessarily done everything right. Hope you're on the road with a smile on your face very soon. Regards.