2004 Cummins ISL 400

[Don Colapietro]

we are working on a 2004 Cummins ISL 400 which died on its maiden voyage. running just fine, then shut off... no spitting or sputtering, just shut off and would not restart. plenty of fuel at the filters. it has a brand new ECM and now shows a code for speed sensor. getting tired of throwing new parts at it. we know just enough to be dangerous. some of the DC voltages at the ECM seem to be low. HELP !  where do we look now?  Don Colapietro 239 940 6199  Thanks





















do                     

[Gene Obie]

Since you indicated possible low voltage issue I'm assuming you've checked all chassis battery connections , especially ground wires. One suggestion would be to start the generator and get a charge going on the batteries - that should raise the battery voltage enough if you happen to be just on the edge of a low voltage issue due to wiring problem.

[David T. Richelderfer]

One other thing, on our coach the Allison transmission keypad MUST show an "N" (Neutral) before the engine will attempt to start.

[Eric Maclean]

Don
Your post states your working on a 2004 with a Cummins and your profile shows you have a 2006.
For clarification we need to know What year make  and model are we working on to get the wiring diagrams right
We need to know whether it's a engine no crank or crank no start.

With that said here goes.
You stated you have poor or low voltage to the ECM

1) First check the ignition side buss bar in the electrical bay to be sure the ignition solenoid is not going. Bad your looking to see if you have a good 12 volts with the ignition on..next check each of the ECM feed circuit breaker on that buss bar to verify it has good voltage going out .

2) depending on the coach in the rear usually in the back of the battery bay there should be an ECM power relay check it to make sure you don't have a bad wire or a bad relay.

3) check. The wiring around the battery area your looking for 2 or 3 fuse holders ( again coach dependant)  these supply direct 12 volts to the ECM and the TCM and can get corroded from the battery acids causing problems.

4) check all your battery cables and ground connections

Hope this helps
Eric

[Don Colapietro]

Thanks for all the great tips. I think we have now isolated the problem to the speed sensor{s}, since there is fuel at the injectors. We're now waiting on a detailed wiring print to see if the sensor(s) generate a signal or if there should be voltage present when cranking.  Don

[Don Colapietro]

Still chasing the no start problem. we have the Cummins wiring diagram and it shows a +5vdc at the engine speed sensor which we don't have while cranking. Possibly a bad brand new ECM??  Is there a fuse somewhere that feeds these sensors?  thinking of hooking a tone generator to the speed sensor plug, but it appears to be coming from the ECM.. Thanks,



don

[Steve Huber Co-Admin]

Don,
Not sure about the ISL, but the 350hp ISC has 4 10amp fuses between the battery and the ECM. Lines are labeled AB ECM Batt Pwr, AC ECM Batt Pwr, AD ECM Batt Pwr, and EM ECM Patt Pwr. See 2004 Monterey Wiring Diagrams, Pg 22.
Steve

[Eric Maclean]

Don
The 5 vdc is a reference voltage supplied from the ECM
Your going to need to check to make sure you have both the 12 vdc ( constant power from the batteries) and the 12 vdc ignition power from the ignition to the ECM then check for the 5 vdc at the engine position sensor plug .
You can also check for 5 vdc at one of the other sensors as well. ( Temperature sensor)

If you have access to Cummins in site software you should be able to see the voltages through the computer as well as sensor reading and crank position RPM.

Word of caution if you have no 5 vdc supply from the ECM and it turns out the ECM is at fault you need find out what is killing me ECMs.( Reference wire or sensor shorted to ground)
Eric

[Don Colapietro]

thanks guys, we're checking now. very frustrating.  ddddddddddddon

[Eric Maclean]

Don
Do you have access to Cummins in site software or a scan tool of any type.

[Don Colapietro]

Yes we do. My friend purchased a fairly extensive scan tool with numerous plugins for different engines.  the only thing that came up was speed sensor. i have not had any time to help him for several days. I understand that the ECM has a constant 12v and a ignition sw. 12v supply. that's where we are now.