Help the newbie please!!

[MCI-RICK]

Sean,

I just turned the bus on and let it warm up.  The sel,cel, trans & battery lights did turn on before start up.  No sel, cel or any other lights turned on while it was running.  I have no temp reading since the sensor is disconnected.  The little tab-type male end snapped off.  It had two of those tabs on the end of the same sensor.  I connected the wire to the second one but it still did not register a temp.  I need to replace the sensor.  If I disconnect the battery, will the codes erase or clear?  or is there another procedure?   

[Sean]

I just turned the bus on and let it warm up.  The sel,cel, trans & battery lights did turn on before start up.  No sel, cel or any other lights turned on while it was running.  ...  If I disconnect the battery, will the codes erase or clear?  or is there another procedure?   

If the lights are not on, then you have no current problem and no active codes.  If there are still codes stored in the ECM, the only way to clear them is with a Pro-Link (DDR).  Disconnecting the battery generally will not clear the codes.

I have no temp reading since the sensor is disconnected.  The little tab-type male end snapped off.  It had two of those tabs on the end of the same sensor.  I connected the wire to the second one but it still did not register a temp.  I need to replace the sensor. 

When you say "no temp reading," I assume you mean on a temperature gauge on the dash (as opposed to a digital readout connected to the DDEC ECM, such as a SilverLeaf VMS or a Detroit Pro-Driver).

Be advised that the sender for any gauge on the dash is completely separate from the temperature sensor connected to the ECM.  If there was a problem with the ECM's temperature input, you would have a CEL and a code associated with that.

The temperature gauge on the dash, and its associated sender, is just there as information for you when you are driving (so that, for example, you could choose a lower gear or slower speed while climbing a hill if you observe the temperature climbing into unfriendly territory).  It is not required for proper engine operation, and, as long at the CEL/SEL and engine stop functions are working, it is impossible to overheat your DDEC-equipped engine -- the ECM will shut it down before damage occurs.

That being said, if you are not paying attention to the SEL when it lights (mine is connected to a bell), then you could be in for a rude surprise when the engine shuts down unexpectedly.  It is recommended that as soon as the SEL lights, you hold in the Stop Engine Over-Ride (SEOR) switch while maneuvering the coach to a safe place to stop.  Safe place, BTW, means the shoulder, not the next exit -- many things that will cause a Stop Engine event can destroy the engine before you make it to an exit, such as catastrophic loss of oil pressure.

-Sean
http://ourodyssey.blogspot.com

[MCI-RICK]

Sean,

I was doing about 40mph and accelerating when I noticed the accelerator pedal felt light and the bus started slowing down.  It was still on but there was no throttle response.  The speed continued to drop and as I pulled into the shoulder it turned off.  This all happened in less than 3/10 of a mile.  I was looking at the dash when it was happening but there were no lights on.  I was puzzled.  I thought it was possibly a low fuel issue.  I had a shut down experience before (low voltage) so I glance at my gauges more frequently now.  I checked the fuel level and had more than half a tank (approx 70 gallons). 

I was only on the shoulder about 15 minutes and I was able to restart it.  I was able to restart it immediately from the rear (engine compartment) controls but when I shut it off and went to the front, it would crank but not start.  I'll take a look at the ecm connector. 

You mentioned a Pro-link (DDR).  Are there different models or types?  or different brands?  I'd like to start looking for one and want as much info as I can get. 

BTW, I took a look at your site.  You have an awesome bus!  My wife and I spent a while looking at the videos and pics.  We were considering two mini-frig units for the kitchen.  I had no idea someone made an under counter model side-by-side.  Please, share info!  Where did you find it?  We prefer the counter space as I guess you do.   We actually thought of having a third mini-frig in the living room area.  We decided to go with a two burner stove also.  We never need more than two anyway.  The convec-micro is on our list too (no oven).  We're glad we took a look at you site (it's now bookmarked)!  As they say, a picture is worth a thousand words.

Great job on your bus!  Enjoy! 

[Sean]

I was doing about 40mph and accelerating when I noticed the accelerator pedal felt light and the bus started slowing down.  It was still on but there was no throttle response.  The speed continued to drop and as I pulled into the shoulder it turned off.  This all happened in less than 3/10 of a mile.  I was looking at the dash when it was happening but there were no lights on.  I was puzzled.  I thought it was possibly a low fuel issue. ... I checked the fuel level and had more than half a tank (approx 70 gallons). 

OK, well I now have to admit that I am puzzled, too.  That's because, in my experience, the ECM will not shut down the engine or reduce power due to a fault without first lighting the CEL or SEL.  However, I'm more an electrical and house systems guy than an engine guy, and I am sure folks here with way more experience than I on these matters can chime in here with some advice.

I will tell you that on your DDEC-controlled engine, the "throttle" is completely electronic -- it consists of a potentiometer (variable resistor) in a spring-loaded housing attached to the pedal.  So the pedal "feeling light" does not make sense to me, other than that we tend to "feel" things like that based on our other senses telling us things.

It is definitely a possibility that the codes you have are from the distant past, and this problem you just had is, indeed, something like a fuel delivery problem.  Even though you had plenty of fuel, something as simple as a dirty filter can produce these power loss symptoms.  I would check out the fuel supply and return systems as well as the air induction system, and replace all filters as a first step.

I was only on the shoulder about 15 minutes and I was able to restart it.  I was able to restart it immediately from the rear (engine compartment) controls but when I shut it off and went to the front, it would crank but not start.

The rear controls bypass some of the safety overrides.  I'd have to look at the wiring schematic for your particular bus to know exactly what is bypassed.  I know that on my bus there is a Kysor shutdown system that is bypassed by the rear switch.

You mentioned a Pro-link (DDR).  Are there different models or types?  or different brands?  I'd like to start looking for one and want as much info as I can get. 

Sorry to say that it is a specialty item and is only made by one company, today Nexiq Technologies (however, if you buy an older unit, it might have a different label on it).  New ones are well over a grand; I've seen them on eBay for as little as $400.  You need the device itself as well as the "cartridge" for your ECM, which sounds to me like a DDEC-II, and the proper connecting cable.  Figure it will cost you $500 or so to get what you need.  You will seldom need this device, so you might find it more cost-effective to borrow one (several folks here on the board have them) or just pay a shop that has one to do what you need.

BTW, I took a look at your site.  You have an awesome bus!  My wife and I spent a while looking at the videos and pics.  We were considering two mini-frig units for the kitchen.  I had no idea someone made an under counter model side-by-side.  Please, share info!  Where did you find it?

Thank you.  The fridge is actually a marine unit made to run on DC (12 or 24 volts).   It is very efficient but also very pricey -- worth it for us since we almost exclusively boondock, and our 330 watts of solar panels will run this fridge indefinitely with power to spare.  If you are interested, though, it is an RF7500 made by Nova-Kool.

If you don't want to go that pricey, there are a number of 120-volt household undercounter models that some in separate fridge and freezer models, which you can mount side by side.

-Sean
http://ourodyssey.blogspot.com