Community Forums

dhlairbus · 01-18-2023, 12:44 PM

Have just finished exercising the coach, during which time I got a check engine light, just after starting the genset while driving in the neighborhood. Then I got another check engine light with a big "!", and small blinking red light at the bottom of the def quantity indicator. Could this be that my def is going bad, or old?
As always, many thanks in advance.

Cthecountry · 01-18-2023, 12:51 PM

You can buy a code reader and see what the problem is and with this code reader you can reset the check engine light so it turns off.
You must correct the problem or the check engine light with stay on
The code reader for my truck was $35

**Lt Dan** · 01-18-2023, 12:53 PM

You should be able to pull the trouble codes on your dash display but it sounds like the start of a DEF head failure. I got similar check engine lights when mine failed. The code reader mentioned above won't work on your Diesel and if it's a critical failure it can't be cleared until the cause is fixed.

Dutch Star Don · 01-18-2023, 05:54 PM

What chassis?

dhlairbus · 01-18-2023, 10:53 PM

It is the Freightliner chassis, with Cummins inline 6, 340 HP.
I purchased a container of DEF, in case the old is going bad.
Will have to check with the refractometer, if I can find it.

dhlairbus · 01-19-2023, 08:18 AM

Update
Checked the LBCU for codes, showed one code...SPN 3031 FM1 9 OC 1
Called Freightliner customer service, they said it sounded like the DEF head was about to fail. Gave him the code, and he said it was another component that is on or in the DEF tank?
He did not think it was old DEF fluid.
He recommended taking to a freightliner dealer.
I am searching the local Lakeland area now, or might find a mobile mechanic.