We are stumped here. If you hook up the pro link to the diagnostic plug and the pro link says "No modules found", is the box dead? There is power to the six way connector. The engine cranks but doesn't even try to start. It has fuel in the filter.
Now for the confession. I, Cary, did a really dumb thing. You know, like not checking the battery cables real careful when hooking up the 24v system? Like when both cables were red? Thinking it wasn't very happy about being hooked up backwards, even though it was just for a minute. Didn't even turn on the run switch on the dash.
So, HELP
If it's dead, anybody have one?
Cary
you should be fuse protected.. look for it. would be step #1 also make sure connector is good= not corroded. these are two most common problems.. fuse would be most likely in your case.. bob
Maybe you got lucky and it just blew the 2 -15 amp fuse going to each head the DDEC 11 is 12 volt only and they don't like 24 volts unfortunately the fuse don't recognize volts only amps
good luck
Do the CEL and SEL both illuminate for a few seconds after turning the key to the Run position? In addition to the two 15A fuses for the injectors, do you have a third 15A fuse for the DDEC relay? My relay is up front in the main electrical panel, but all three fuses are in the engine room.
John
The two fuses inline to the injectors look fine. There was another inline fuse in a harness in the same area and it appeared ok also. There doesn't seem to be any sel cel sto lights. There is a button to push for check ddec. I found a breaker in a panel box that was for the ddec and it wasn't blown. When you turn on the run switch the check engine light comes on and then goes out after about five seconds. Pretty sure the check engine light flashes the codes. This is in the Neoplan by the way.
Cary
When all else fails check fuse holders and continuity of fuses.. never assume anything.. do wish you the best..
No codes should be flashing unless you push the override switch active codes are flashed from stop engine light the inactive codes are flashed through the check engine light I presume you have a diagnostic request switch ?
Don't know your system as to what is 12 and what is 24 volt, but if you have vanners there is a circuit breaker reset - HTH
I don't know about other coaches, but when a Prevost owner swaps out chassis batteries and miswires them the end result often is the DDEC is not getting 12 volts and therefore the coach will not start.
My first place to look would be to verify DDEC is getting power where it is supposed to. A Prevost has multiple power sources feeding DDEC.
From the 111 on the DCEC's don't care if it is 12 or 24v supply Cary says it has power check the ground now
But isn't DDEC II a 12 volt system?
Yea Jon the DDEC 11 is 12 volt only remember not long ago here the guy working on the Prevost hooked the DDEC 11 up to 24 volts and cost him a new ECM and then he had electronic transmission problems I wonder if he ever got that bus on the road ?
On a DDECII it ain't gonna start if the voltage drops down around 12.2, they are fussy that way. Get your batteries up in the 13V range and see if it starts.
We will check the fuses and holders again. We will check the vanner. The power going to the ddec is 12.8 volts. It turns over really fast. We will check the codes by Clifford's directions. It has a ddec diagnostic button. Maybe, will try and crank it with the override switch pushed. The transmission is 12 volt. There are two breakers in the battery compartment that say they feed the injectors that had blown. But they aren't blowing anymore.
Cary
Don't just check "visually" on the fuses. Use an ohm meter an make sue you are getting close to zero ohms thru the fuses & holders.
While you have the meter out go ahead and check to see that you are getting 12+V to the ECM and the both of the injector wires.
I've seen and heard many times the fuses are good they look fine when they in fact were bad when checking with a meter.
;D BK ;D
Spent some time with the ohm meter checking breakers for continuity. Checked all the cube relays with a relay checker. Everything seems to have breakers and not fuses. So far all the readings are .3 ohm or lower. Found one bad one, but that was on the back up lights. The ground wires on the six way ddec box showed .3ohms. Grounded to the body for the checks.
The only thing that seems different is the check engine light is staying on a shorter period every time we turn on the run switch.
Cary
Well, we have been reading to trouble shooting book. Clifford has it right. 600 pages of not much help. Anybody have any more ideas? Maybe some place we can pick up another ddec unit.
Cary
This is my best guess. Back probe the ECM power connector with the ignition on and everything connected. If you have battery voltage between the power supplies and grounds and still no starting it's likely the ECM is fried.
Ken
Yes, it has power on the six way power connector.
Another question. If the thing is fried, how hard would it be to change to DDEC IV? Everybody seems to think that is better.
Don and Cary
I'm no DDEC expert, but could a Detroit dealer test your DDEC to see if it is working or not before you spend money on another one?
What engine is this for? If it's an 8V92 I may have one still one an engine in a bus I'm parting out.
I have no idea if it's good or not. Supposedly the engine was running when they took the bus out of service do to water in oil. But I have no proof of this.
;D BK ;D
One side of the power connector will feed one bank of injectors , the other side will feed the other bank. the ground wires in the middle of the connector should go directly to battery ground.
If you make up a wiring harness that fits the ECM power plug and connect it to a separate battery and crank the engine over if the engine starts check your wiring if it doesn't , the ECM is fried. I think the connector that connects the Throttle position sensor is the same configuration as the ECM power plug. Cheers Gerry
Yes, this is a 8v92 turbo in a Neoplan. The transmission is a 748 with a retarder if that makes any difference.
The power is going into the box, but obviously, nothing coming out the other side.
Don and Cary
Hey guys whats the norm for getting codes the old fashion way with that diag button. If I might ad some other trucks you hold the button in and turn the key on then count the blinks, or some just read the description. I am going to look around for a pin out schematic for a 92 year model with a 6v I suppose it would have both models very close to the same. I will try to help out when i get some tips Keep up the good work.
Later