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Maxm · 03-07-2014, 12:37 PM

Hello all, my apology for not introducing myself and building some re pore first. I'm afraid I have a question and hope someone tells me it's simple. My father passed away last month and owned a 2001 Monaco M40PBD with 55k miles on it. Of course it is the 330 cummins and he had all service done on a regular basis. I'm helping my mother sell it and found a buyer but when we went to test drive I have a red WARNING light (not check engine) and no acceleration. I'm hoping someone will tell me that this may be an operator error. The rig hasn't been moved for about 4 months but everything seems to work fine, all batteries are up and no apparent problems I can see but I am an extreme novice at this.

Thank you in advance for any suggestions.

Max

Steve Ownby · 03-07-2014, 01:31 PM

Quote:

Originally Posted by Maxm

Hello all, my apology for not introducing myself and building some re pore first. I'm afraid I have a question and hope someone tells me it's simple. My father passed away last month and owned a 2001 Monaco M40PBD with 55k miles on it. Of course it is the 330 cummins and he had all service done on a regular basis. I'm helping my mother sell it and found a buyer but when we went to test drive I have a red WARNING light (not check engine) and no acceleration. I'm hoping someone will tell me that this may be an operator error. The rig hasn't been moved for about 4 months but everything seems to work fine, all batteries are up and no apparent problems I can see but I am an extreme novice at this. Thank you in advance for any suggestions. Max

That warning light can have several inputs. I would check coolant level first as that is pretty simple.

Maxm · 03-07-2014, 01:43 PM

Steve,

Thank you so much for the quick response. Is that the reason the engine will not accelerate? If the level is low will it reset it self when I top it off? I understand it could be many things.

Thanks again,

Max

MandG-Fun · 03-07-2014, 01:47 PM

Quote:

Originally Posted by Maxm

Steve,

Thank you so much for the quick response. Is that the reason the engine will not accelerate? If the level is low will it reset it self when I top it off? I understand it could be many things.

Thanks again,

Max

Max, Perhaps a silly question but I assume the person test driving knew to disengage the parking brake? Also, since it has been sitting for a while did you let it warm up some? When you put it into gear do you feel any engagement of the transmission (either in drive or reverse)?

Maxm · 03-07-2014, 01:55 PM

Quote:

Originally Posted by MandG-Fun

Max, Perhaps a silly question but I assume the person test driving knew to disengage the parking brake? Also, since it has been sitting for a while did you let it warm up some? When you put it into gear do you feel any engagement of the transmission (either in drive or reverse)?

It was allowed to warm up good and yes you can move it around when you put it in either reverse or gear. I believe it is a drive by wire system and you just have no throttle at all. It moves at whatever speed the idle is. The park brake was released and just on when the photo was taken. Thanks for your thoughts.

Max

Steve Ownby · 03-07-2014, 02:12 PM

Quote:

Originally Posted by Maxm

Steve, Thank you so much for the quick response. Is that the reason the engine will not accelerate? If the level is low will it reset it self when I top it off? I understand it could be many things. Thanks again, Max

I guess I read right over the "no acceleration" issue. Since you have that issue along with the light, I suspect the ECM is not getting data from a sensor. May need to have a Cummins shop hook their computer up.

If you are up for a little troubleshooting, you could unhook the negative chassis battery cable for a couple of minutes and give the engine ECM a chance to reset. Also make sure the chassis battery has a full charge. Slightly low voltage can cause some issues.

Again these cost only a little "sweat equity".

Maxm · 03-07-2014, 02:20 PM

Steve,

Do I need to unhook the batteries or can I can I turn them off with the master switches? If I am seeing the batteries correctly the coach has 4 batteries and the engine uses two that are in front of those. Do I have to disconnect the coach or engine, or both?

Thanks so much for your help.

Max

Steve Ownby · 03-07-2014, 02:32 PM

Quote:

Originally Posted by Maxm

Steve, Do I need to unhook the batteries or can I can I turn them off with the master switches? If I am seeing the batteries correctly the coach has 4 batteries and the engine uses two that are in front of those. Do I have to disconnect the coach or engine, or both? Thanks so much for your help. Max

Max,

On many coaches and most Monaco's, the engine ECM bypasses the master switch so to be sure of killing power the the engine computer it's necessary to physically disconnect the chassis batteries. The 6 volt house batteries are not connected to the engine, only the two 12 volt chassis batteries. If you disconnect the negative cable, that will cut the circuit and you won't have a live cable that could touch a ground point & cause other problems.

Maxm · 03-07-2014, 03:30 PM

Steve,

Thank you for the information. I am relaying this to my brother who is there now and I will update you as soon as he gets a chance to try that. I knew cars got OBDII ECM's in 97 and you could no longer clear most codes with a power down but I wasn't sure how the ECM was on one of these. I know it has no feedback closed loop systems from exhaust so it would make sense that they would use a basic ECM. I will update and you thanks for your thoughts.

Max

Steve Ownby · 03-07-2014, 03:45 PM

Quote:

Originally Posted by Maxm

Steve, Thank you for the information. I am relaying this to my brother who is there now and I will update you as soon as he gets a chance to try that. I knew cars got OBDII ECM's in 97 and you could no longer clear most codes with a power down but I wasn't sure how the ECM was on one of these. I know it has no feedback closed loop systems from exhaust so it would make sense that they would use a basic ECM. I will update and you thanks for your thoughts. Max

I think it depends on the reason for the light. If the ECM has just lost communication with a sensor then a reset might reestablish the data.

Maxm · 03-07-2014, 04:23 PM

Quote:

Originally Posted by Steve Ownby

I think it depends on the reason for the light. If the ECM has just lost communication with a sensor then a reset might reestablish the data.

I think the problem has been isolated. Seems we had guest that have a desire for the sweet taste of silicone.

Maxm · 03-07-2014, 07:16 PM

I will say the good news is they got the one harness and some foam and that is it. No other damage to be found. Thanks for the input, it's always good to bounce things off others and knowing very little about coaches it helps, but I have a very large mechanical background which helps.

Thanks again.

Max

Maxm · 03-08-2014, 12:59 PM

I got the wiring fixed and have throttle control however i still have a warning light and loss of power. Coolant is full, oil and trans appear good. What else does the warning light look at? How can I check codes in the ECU or ECM?

Thanks again.

mlh2013 · 03-11-2014, 08:59 PM

do you get any turbo boost? If not my diplomat did something similar warning light would come on and I would lose power. I changed fuel filters and light was off and had power back. problem solved.