Check Eng. & Stop Eng. Lites

[LarryB]

After a couple of hours of 50-60 mph winding road with use of hi and low jake and manual downshift we were stopped in Traffic. The Check Eng. lite came on steady and the Stop Eng. lite blinked on and off a couple of times. All eng gage readings in the normal range, oil level and coolant levels were checked 'good' prior to the drive. OAT ranged from 89 to 76 degrees.

To turn off the Check Eng. lite I shut down and restarted the engine. Drove without any warning lites for about 30 minutes and while stopped for traffic again, the same occured again.

Any Ideas folks? Thanks!!

[Loc]

Larry,

With a 2000 XL you should be able to get the codes off of the DDEC computer by switching the DDEC read switch (typically located in the area below the drivers seat where the steering gearbox and windshield washer fluid container is located). Then turn the key to on and read the flashes on the stop engine and check engine lights. The Prevost owners manual will have a page for decifering the codes and a recap of how to read them. I would guess it is a low coolant sending unit on the surge tank above the engine on the left hand side.

Loc

[Jon Wehrenberg]

If it turns out the low coolant sensor is the culprit, check the wiring at the terminal, some instances of it being bound to tight with nylon wire ties have created issues. If it turns out to be a bad sensor, a jumper between the terminals on the wire harness will make the codes go away, but you lose the protection so make sure you keep an eye on the coolant.

When you do get stop or check engine lights, always read the codes. If you get a code and you do not have the secret decoder ring, post it and we can interpret what it is saying. For a fee. A large fee. And the answer may even be correct. Or not.

[JIM CHALOUPKA]

Larry, this is the secret decoder ring Jon is talking about.

[LarryB]

OK, I see about the FEE part of this deal later, much later. I'll check the codes and see whats what.

Thanks Guys!

[LarryB]

Loc, I looked for the switch you refer to but have yet to find any switches in that area. I did find some of the DDEC boxes but no switch on any of them.

[Jon Wehrenberg]

Larry,

There should be a way for you to access the codes. Obviously if you can get to a DD shop they can read them, but you should have a way to get them to flash for you on the dash.

The way to read them should be described in the Prevost manual, or if CC has modified the dash there may be a way CC has provided for you to get them to flash.

On my 87 I could put a jumper between terminals A and M on the plug for the reader, and as long as that jumper was there the light would flash and I would get the audible and from either listening to the thing or counting blinks of the light you could determine the code. It has been my experience so far that most codes are sensor problems rather than problems with the engine so they are usually not difficult to repair.

Perhaps someone with your vintage coach can jump in here and tell you how to access your codes. Same thing with your power issue. You need CC specific advice on these.

[truk4u]

Larry,

You can use the check engine light as the source for your code. I don't remember the sequence, engine off, throttle pressed twice or something like that and it will blink the codes. It's in the books and if you don't have it, I'm sure someone here will. I assume you don't have a Pro Driver.

You have a switch in the steering compartment, but it's for blink codes on the ABS.

[LarryB]

Thanks for the help, I'm just going to have to dig deep for the sequence to get the codes, I believe I Did hear 2 beeps as the stop engine lite came on and off so not sure this beeping is related. My DD code pamphlet does not speak of beeps only flashes. The pamphlet describes how to get the codes by "pressing and holding a switch. I'll keep looking.

[Jon Wehrenberg]

I use a reader now, but back in the old days when I jumpered between two terminals I got the flashing light and the beeping. Having an audible, if it does it any more was good because I could jumper the terminals in the steer compartment, hear and count the beeps, and then remove the jumper. I did not have to get back in the coach to see the light flashing.

[LarryB]

Jon, I'm told by a CC tech that they didn't equip this bus with a reader switch. Go figure!

Anyway I have a DD tech come out to read the codes.

Thanks again.

[Jon Wehrenberg]

Larry,

Codes are a Prevost issue. CC builds the house, not the bus. However, CC interfaces some of their systems with the bus, blurring the line between the two. They are unique in that respect. He is probably right in that their dash may not have the feature for flashing codes built in.

But not knowing a damn thing about how CC has built their dash displays, I would guess there is still a way you can access the codes without a reader. If not, for your own protection try to get a reader or install a ProDriver that will display active codes.

There is nothing worse than to be along side the road with red and orange flshing lights on your bus scaring you, when all you may have is a bad sensor. If you are coming to OKC there are a number of us with readers which occasionally show up on ebay. As long as the reader has software specific to your DDEC level (I think you are DDEC III) you can plug in the reader and in plain English read what malfunction is causing the warning lights.

[hhoppe]

As I remember solving a similar situation I held down two shifter selection buttons simotanious and the code lights blinked their message.
Are you sure there is ample supply of water in the water resevoir and engine oil is not low.

[LarryB]

Harry, The coolant level was fine.

I had a Trucking Co. Mech. plug in their DD reader and the computer showed no recent codes. That to me is strange unless my 'Com puter Dash' is acting up and giving me lights in error.

Thanks

[Jerry Winchester]

Larry,

I had that same problem with my XL coach and it turned out to be the oil pressure sensor. But this did show up on the DDEC as "Low Sensor Voltage" and it was the same code manually reading it and then reading it with the DDEC reader.

But if your codes are clean, then I am at a loss as to why it is happening and I would have thought that the CC part and the Prevost engine part of the systems would not be integrated. But then again, I'm not surprised by anything CC does with respect to electronics and sensors.

[Jon Wehrenberg]

Since mechanical problems never repair themselves unless you purchased that option for your coach, now is the time to figure out how to read the codes. This will happen again. When it does you need to be able to find out what is doing it. Some codes, specifically those related to low coolant, low oil pressure, high coolant and oil temperature will shut the coach down. You get the warning, and then a few seconds later the engine gets shut off. Not good.

[LarryB]

Jon, I agree but, what would you suggest? I'm sitting in a Hay field having just had the DD read. If the problem is DD related it should have shown a code, it did not. Why Not? So in the absence of a code I have to believe the problem is maybe some other system like maybe, the computer dash?

[Denny]

Larry,

Did you get the right side power fixed? I sent you a reply on the post you made about no power since I had the same problem but it seems to have gotten lost; did not stay on the site for very long so not sure you had a chance to read it. I checked and it is still on your "power lost" post.

[Jon Wehrenberg]

Larry,

I'm far from an expert on DDEC codes. However, I do know we can get intermittent codes due to sensor issues, ground problems, real problems, or just because the bus decides to play with your head.

But no matter the cause, they will in some cases shut the engine off. The DDEC does not have the ability to differentiate between a sensor that has failed or a real problem.

Now that I have sufficiently scared you and probably everyone else contemplating a coach here is some things you can do. First, see if you can find the magic trick to flashing your codes. I cannot believe that is not possible. Maybe some of the other CC owners can give you hints on things to try.

In the meantime scour ebay and keep looking to find a reader. With the software for your DDEC version it may cost you as much as $500, but with the reader you can actually monitor codes while driving. That is going to be the key to chasing down the intermittent codes because as you now know, if they are not in memory DD cannot help you.

A final thing you can do is turn your coach over to DD, along with your wallet and have them find the problem. With so many hundreds of connectors and potential failure points Dick Tracy would have a hard time sorting things out, so that solution could be very expensive and yet still not resolve the problem.

Keep in mind that there is a time to react and a time to monitor the situation. If your only warning is a check engine light (orange) it is telling you something will require attention. You can still drive the coach because it will not shut down, but there is something that has gone out of the parameters established by DDEC. If you get the stop engine light (red) you need to get to the side of the road immediately because in a very short period of time the engine will shut down. You can over-ride the shut down by using the over-ride switch if needed to get to a safe spot.

If anyone has your version of DDEC and is willing perhaps they can send it to you so you can hook it up and place it next to your seat while you drive. In that way when the check engine or stop engine lights come on you or your wife can read the problem.

Any POGGERs have a reader that can help Larry? Larry, I have DDEC III. If that works I can send you mine. I have an old reader and it needs a cigarette lighter to power it.

[LarryB]

Jon, Thanks for the offer of the Reader, but I am going to try to get to the Seattle area this AM and I'll look for a Reader in that area. I'm in a small town on the Olympic Peninsula and HAVE to move today. I will nurse it that far and deal with there. All help from this area has been used.

I'm not sure if I understand you but, are you saying that intermittent codes will not leave a code?

Jerry, Don't know exactly what you mean about the CC application and setup. The only thing different should be the computer dash. DD info to lights or the computer dash should all be the same Info except the method of seeing said light. Am I missing something?

[hhoppe]

Larry having been shut down in the middle of a narrow road because of a sensor failure. :eek: I wish to offer: Check your manual to make sure you know the sequence of events it takes to over ride the stop engine long enough to get safely off the road. With that knowledge I would not hesitate to get on the road to a DD shop to have it checked out. Do not hesitate to call Prevost emergency phone number, they can help.

This is a glaring example of why we should all be carrying spare sensors on board. Examine the sensors and make sure you have adequate tooling to fit and leverage to remove the old ones. Most sensors are located in very difficult locations to get to. A list of sensors with part numbers was recently listed on this forrum. Good Luck your going to make it to a destination where help is available.:)

[Jon Wehrenberg]

Usually all codes remain in memory. There is an exception to that however.

CBs #19, 20 and 21 in the rear electric box are always hot, even when the main chassis power switch is turned off. If all electric is lost from the chassis batteries, then the memory will be wiped clean.

I do not know if all codes are retained in memory. I am sure there are some codes that are not retained. But that is just a guess.

[LarryB]

Harry, good advice, thanks tfor the help.

Jon, thanks for the help. Maybe I screwwed up something when I installed the charger for the chassis batts.

[truk4u]

If your not getting any stored codes via the DD reader, then possibly there is a problem with a daughter/mother board in the basement or a combination of the digital dash and associated circuit boards behind the dash. It's very difficult to trouble shoot all the CC boards and circuits and some of us have been down that road. Don't know if Nick Hessler is still out there, but CC isn't going to be much help to you. On the non-digital dashes, if the check engine light comes on, there is a code stored.

Like Harry stated, know how to use the override (yours should be a foot button on the floor) in case you get in trouble and can't get off the highway.

[LarryB]

Tom, thanks I was not sure what the foot buttom was all about .
Thanks again.

[Jon Wehrenberg]

I think he was saying the check engine and stop engine lights come on so often you might as well have a foot button so you don't have to reach to the dash with your hand to press a switch.

As a non-CC owner I was not aware the DD codes are run through the CC electronics. That puts a whole new spin on this so Larry, you really need CC specific advice. Nick Hessler does know his stuff and Miles is the POG expert.

[truk4u]

Jon,

The 2000 CC has a foot button on the floor for the override instead of a dash switch. I thought it was a dumb idea because your always hitting it with your foot and I believe Jamie experienced some warning lights due to accidently pushing the button with his foot.

[JIM CHALOUPKA]

Larry, the last contact number I have for Nick Hessler is 541.321.2545.

He is in your part of the country. I am not home and away from my records so can not give you anything else.

JIM

[LarryB]

Thanks Jim for the info on Nick Hessler I'll give him a call.