Packed & ready to pull out and then.....

[planopat]

after 20 minutes or so of engine idling, solid check engine light comes on. Engine temp appears normal.

Half an hour later the Onan dies. One A/C unit was the only draw and I let it rest for awhile and when restarted it ran for 5 minutes and died again. The dash switch repeated 3 blinks. Does the dash switch offer other codes or do I have to use the switch that's on the gen itself?

Both were serviced at Oasis 3 weeks & 40 miles ago - fuel / oil filters etc.

[dave0368]

Fault codes and how to read them for the Onan start on page 41.

https://www.norwall.com/product_pdfs...015.pdf#page33

[dave0368]

The switch for the Onan will display fault codes:

6.2 Fault Codes
The generator set control contains extensive diagnostics to detect shutdown faults. Following a fault shutdown, the control indicates the fault code by flashing the numeric code on the status indicator in the control switch.
Determine the fault code as follows:
• 1 flash indicates a high engine coolant temperature.
• 2 flashes indicates a low oil pressure fault (Code 2 fault).
• 3 flashes indicates a service fault (Code 3 fault).

Press STOP/PRIME on the control switch once to have the 2-digit service fault code flash.
The 2-digit code consists of two sets of flashes. The first set is of flashes represents the 10s digit of the code. After a brief pause, the second digit of the code flashes representing the unit digit of the code. This is followed by a long pause before repeating the flashing of the fault code.

For example, Fault Code 36 appears as: blink-blink-blink—pause—blink-blink-blink- blink-blink-blink—long pause—repeat
Press STOP/PRIME to stop flashing the fault code.

[planopat]

I couldn't get a code using the dash switch but did get code 36 using the one on the gen. Can't be fuel level, there's 75 gal there. Air filter should be good, only about 50 hours on it but I'll check in the AM. Thanks.

[dan-nickie]

You can check some engine codes via the LBCU on the dash

BTW, I have read that it may display an error code for idling the engine too long. I believe freightliner recommends no more than 10 minutes idling.

[planopat]

I've looked at the LBCU instructions a dozen times & get the parts except for how to get to the diagnostics section but I'm going to look again at my print out chart. Maybe it is the idle time although I drove about 1/2 mile before parking it (more stuff to load) and during that time the light did not go out. Can't say I got up enough speed. Test drive in the AM. Thanks.

[dan-nickie]

Also read that 3 cycles of the engine will turn off the excessive idle display. Don't know if it's all true.
I'll see if I can help get you started on the diagnostics in the next post. It'll be from memory,

[dan-nickie]

1. Turn on key, engine off.
2. Toggle joystick left to turn off Checklist display.
3. Hold joystick right for more than 5 seconds.
4. Scroll down to diagnostics.
5. Toggle right to enter diagnostics.

That's about all I remember so I hope it gets you started.

[planopat]

Thanks for your help Dan. I'll give it a try in the morning.

[planopat]

Engine Fault 1 of 1
SPN 3031 FMI 2 OC 1

Now I have to find out what that means.

[dan-nickie]

This link may or may not help. I have read that the 1st thing to do is check all the connectors around the def tank.

https://www.justanswer.com/medium-an...mi-2-2013.html

[formerFR]

generally that 'alert', with the outline of an engine, is NOT engine related, but rather EMISSIONS related, and nothing to do with your engine.

Mine came on recently, and I didn't skip a beat while driving back another 200 miles to home, then not worrying about it - it's happened on more than a few occasions before and it was either a Nox sensor on the exhaust, replaced by Cummins, or a DEF quality issue, that then went away on it's own after some time.


as for the Onan generator shutting off, the two are not related, but the generator sometimes will have these symptoms after either the generator has been serviced, where the fuel in the fill tube was replaced with air, or the fuel tank for the coach dipped below 1/4 tank, causing the same issue.
I have this issue from time to time, but it's no biggy... just restart the generator, hold the switch for a few seconds even after it has cranked, and you should be good to go. You may even have to do this several times.

[planopat]

Originally Posted by dan-nickie

This link may or may not help. I have read that the 1st thing to do is check all the connectors around the def tank.

https://www.justanswer.com/medium-an...mi-2-2013.html

That article agrees w/ what Cummins tech told me via phone, “def fluid temperature sensor sees that the tank temp is too high or too low for ambient.”
I’ve run for about 7 hours w/o a problem (light still on). Don’t know if the 10 hours referred to in the link resets after cold stop or if I only have a couple of hours left.

[planopat]

Originally Posted by formerFR

generally that 'alert', with the outline of an engine, is NOT engine related, but rather EMISSIONS related, and nothing to do with your engine.

Mine came on recently, and I didn't skip a beat while driving back another 200 miles to home, then not worrying about it - it's happened on more than a few occasions before and it was either a Nox sensor on the exhaust, replaced by Cummins, or a DEF quality issue, that then went away on it's own after some time.


as for the Onan generator shutting off, the two are not related, but the generator sometimes will have these symptoms after either the generator has been serviced, where the fuel in the fill tube was replaced with air, or the fuel tank for the coach dipped below 1/4 tank, causing the same issue.
I have this issue from time to time, but it's no biggy... just restart the generator, hold the switch for a few seconds even after it has cranked, and you should be good to go. You may even have to do this several times.

Yes,I’m hoping it will go away'!

I’ve tried to start the gen probably 20 times in about 8 hours and the fault code is pretty generic...air filter, fuel tank too low etc. interestingly I was told today similar to your comment that these symptoms seem to act up soon after service. I’ll keep trying to start but I’m thinking that fuel filter replacement is next.

[Oscarvan]

There's a discussion on the DEF code here:

Spn 3031 fmi 2 - iRV2 Forums

Not sure how helpful it is. Did remind me that Emissions warrantees are frequently longer than drivetrain.

My next call would be to the FL hotline.

[planopat]

Onan back on line. Oasis service 3 weeks ago installed fuel filter backwards. Ugh!

Engine light? Have to get back on that.

[dan-nickie]

OMG. The main reason I prefer to do my own maintenance when possible.

[Oscarvan]

Originally Posted by dan-nickie

OMG. The main reason I prefer to do my own maintenance when possible.

This.

[planopat]

And on the 6th day.... and 1200 miles later, the check engine light went out. One tech said it took x amount of re-starts. Another said restarts only after not running for 8 hours. I think it has more to do with phases of the moon. At any rate both my problems have resolved. Thanks to all.

[dan-nickie]

Good deal. Have you checkef the LBCU to see if amy codes are still in there?