Broken DEF Header and possible workaround

[Jim]

Failure of the temperature control valve in the coolant lines to/from the DEF header are well known. Temporary fix is to just clamp off the coolant lines until a proper fix can be done.

So I'm laying in bed this AM and I hear an emergency vehicle going down the road, probably an ambulance or firetruck. And I wondered to myself, what do these guys do when they have a DEF header failure? Get out and clamp the intake hose? Or is there some sort of bypass built into these vehicles that we, as RV'ers, don't have access to?

 

[Rich W.]

So I'm laying in bed this AM and I hear an emergency vehicle going down the road, probably an ambulance or firetruck. And I wondered to myself, what do these guys do when they have a DEF header failure? Get out and clamp the intake hose? Or is there some sort of bypass built into these vehicles that we, as RV'ers, don't have access to?

Emergency vehicles are exempt as is agricultural harvesting equipment - they still have the emissions systems but they wont derate in the event of failures. The exemption should have been extended to anyone with a domicile with these emissions systems but in the infinite wisdom of the grand decision makers, we aren’t that important.

https://www.cummins.com/fire-and-emergency/vehicle-emissions-derate-exemption

Apparently what we experience doesn’t quality as “undue hardship”.

 

[NWIP]

Question about diagnosis if not to complicated, was it associated with codes? I do monitor DEF temp on BlueFire and possibly would indicated there.

 

[Jim]

Question about diagnosis if not to complicated, was it associated with codes? I do monitor DEF temp on BlueFire and possibly would indicated there.

Per the Freightliner shop.

"HOOKED UP LAPTOP AND CHECKED FOR FAULTS. HAD FAULT 1713, FAULT WAS INACTIVE WITH 9 COUNTS. TROUBLESHOOTING LED TO REPLACING DEF TANK TEMPATURE SENSOR.

 

[Rich W.]

Per the Freightliner shop.

"HOOKED UP LAPTOP AND CHECKED FOR FAULTS. HAD FAULT 1713, FAULT WAS INACTIVE WITH 9 COUNTS. TROUBLESHOOTING LED TO REPLACING DEF TANK TEMPATURE SENSOR.

Didn’t you also have a SPN 3363? I’ve lost track at this point but that is the common code for this problem.
Edit - I clicked the link and 1713 is the Cummins code for SPN 3363 FMI 16. I’m a little slow this morning….So for those using the LBCU or typical code readers to view fault codes, you’ll see SPN 3363 and one of several possible FMI codes depending on the specifics.

 

[Jim]

Didn’t you also have a SPN 3363? I’ve lost track at this point but that is the common code for this problem.
Edit - I clicked the link and 1713 is the Cummins code for SPN 3363 FMI 16. I’m a little slow this morning….So for those using the LBCU or typical code readers to view fault codes, you’ll see SPN 3363 and one of several possible FMI codes depending on the specifics.

Yes, Fault Code: 1713 PID: SPN: 3363 Aftertreatment Diesel Exhaust Fluid (DEF) Tank Heater

 

[Texas Clodhopper]

Excellent thread, Jim. I think I know what I'll be doing tomorrow.

 

[flyboy013]

“Obviously the right answer is to replace the OEM valve just in case you will be driving in freezing temperatures”

You can’t just replace the OEM valve because its part of the DEF header.

While I'm not an expert here, from what I understand the DEF heater valve is upstream of the DEF head. It's not internal to the DEF head.

 

[flyboy013]

@Jim - Here's the Cummins QuickServe document for the fault code. It talks about the valve that's upsteam of the DEF Header.

The diesel exhaust fluid tank heater control valve is located near the diesel exhaust fluid tank. Specific location will vary depending on the OEM. The tank heating coil is internal to the diesel exhaust fluid tank.

 

[Jim]

@Jim - Here's the Cummins QuickServe document for the fault code. It talks about the valve that's upsteam of the DEF Header.

I'm not sure where it would be if it isn't part of the DEF header itself. But even if it wasn't, keeping the heated engine coolant from entering the DEF header, and thus not heating the DEF, is what we're trying to achieve. And bypassing the DEF header altogether achieves that.

Or am I not understanding the question?