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pdaniels
New Member

8 Posts

Posted - 01/07/2020 :  06:28:20 AM  Show Profile  Visit pdaniels's Homepage  Reply with Quote
2016 Bluebird ISB, Allison. FC3242 mechanical system not responding or out of adjustment. Does anyone have a clear answer on what ambient temperature the coolant valve should be commanded to open? Also is there a test through Insight that will command this valve to operate, I tried pump heater test but that does not test coolant valve. Have left unit outside for a couple of evenings in VT tank temp has gone down to 32 degrees but still not commanding valve to open.

Bluenozer
Advanced Member

Canada
354 Posts

Posted - 01/07/2020 :  09:08:18 AM  Show Profile  Reply with Quote
not sure on temp for that valve to open DEF freezes at -11C , I believe there is a time parameter into the circuit also , and that test should open valve for coolant to enter, heard alot about bad relays in these BB buses try a new one and re-test

OEM trained in wiring and all engine platforms for 20 years
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pdaniels
New Member

8 Posts

Posted - 01/08/2020 :  3:46:12 PM  Show Profile  Visit pdaniels's Homepage  Reply with Quote
Thank you for the info, we will definitely be looking at the relay. Try and keep you posted.
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Gearbox
Active Member

USA
39 Posts

Posted - 01/09/2020 :  06:58:27 AM  Show Profile  Visit Gearbox's Homepage  Reply with Quote
Verify coolant flow through the valve, has the coolant system been open recently for any other repairs?
All coolant valves open etc.

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pdaniels
New Member

8 Posts

Posted - 01/10/2020 :  2:27:05 PM  Show Profile  Visit pdaniels's Homepage  Reply with Quote
Cooling system has not been opened up at least not recently. Coolant valve has been changed, relay appeared to be & tested OK. At ambient 17 degrees after changed valve it was commanded open, not immediately like DEF lines and pump but after engine started to warm. Slowly tank temp rose and valve eventually closed. Today at ambient 32 degrees and tank temp 33 took for test drive, valve never commanded open, line and pump module heaters activated, doser valve opened and closed, no faults, returned to shop with tank temp of 35 degrees. Returned bus to service, skeptical at best.
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Bluenozer
Advanced Member

Canada
354 Posts

Posted - 01/13/2020 :  02:12:45 AM  Show Profile  Reply with Quote
I think it has 40 minutes to raise DEF tank temp. before logging a code

OEM trained in wiring and all engine platforms for 20 years
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pdaniels
New Member

8 Posts

Posted - 01/13/2020 :  12:46:57 PM  Show Profile  Visit pdaniels's Homepage  Reply with Quote
Thank you for info., could it possibly be 10 degrees over span of 40 Mins.,?
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Bluenozer
Advanced Member

Canada
354 Posts

Posted - 01/14/2020 :  02:34:19 AM  Show Profile  Reply with Quote
sounds like it

OEM trained in wiring and all engine platforms for 20 years
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exmod110
Senior Member

132 Posts

Posted - 01/21/2020 :  1:00:08 PM  Show Profile  Visit exmod110's Homepage  Reply with Quote
from the cummins book.
if ambient temp below 25f the def controller will command the defrosting system to go into defrost state. the dosing unit will turn on its internal heater to defrost any def inside it. if applicable, will also turn on the heated lines. if the def tank temp drops below 23f the def tank coolant valve will be commanded open by def controller. the system will not prime until every component is defrosted.
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g0ttadrift
Senior Member

USA
141 Posts

Posted - 01/22/2020 :  12:44:50 PM  Show Profile  Reply with Quote
thanks exmod.....good info to know.
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pdaniels
New Member

8 Posts

Posted - 01/22/2020 :  3:44:19 PM  Show Profile  Visit pdaniels's Homepage  Reply with Quote
Wanted to let forum know that upon road test with lap top at about 25-27 degree day I did see defrost initialized on pump control unit & heater lines activated we had already replaced tank heater valve. I did not see the valve commanded to open but tank temp may have not been cold enough like exmod110 mentioned. We returned the unit to service and have not had another problem and since have gone through a few single digit days. I remain a bit baffled why all heater components would not come on at same time at the same temperature controlled by temp of DEF in tank. Thanks all for the input.
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exmod110
Senior Member

132 Posts

Posted - 01/23/2020 :  12:56:21 PM  Show Profile  Visit exmod110's Homepage  Reply with Quote
the book mentions 2 modes, defrost and maintenance. the latter is to prevent refreezing after the system has primed.
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