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aw12345

DEF troubles on mp7 engine

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This truck was driven till the src system derated to 5 mph. Got the derate resolved and the def system working again.

Now I am stuck with a active code 128 fmi 14 which comes with the cryptic description special instructions.

The driver information display informs me that the 5 mph derate is cleared, but the system is evaluating DEF quality.

Where do I go from here, this truck needs to be on the road tomorrow

Thanks in advance

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If everything is working corectly the scr system will monitor the process for the next couple hundred miles then will turn the pending fualt code off.

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So it just needs to be driven? ran about every test I could with premium tech tool and the system works fine all other active codes went inactive and all tests passed.

Another question a I am seeing loss of power to the def pump code pop up on more than a few of our MP7's and MP8'sw is there a common issue with that?

Thanks

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A lengthy road test/back into service or performing up to 2 consecutive regens should clear the fault. The acm is evaluating info sent by the nox sensors and once everything looks good it clears the fault.

The loss of power to the def pump code could be corrosion on harness pins or short/open in def pump harness, we've had to replace a few def pump harnesses because of this.

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Thanks, will try the back in service tomorrow, if not will do the back to back regens.

I have seen the DEF pump loss of power code on about 5-6 different trucks now all with a milage between 200.000 to 300.000 miles. 1 2011 MP8 and the others are all 2010 MP7's.

Corrosion isn't a terribly big problem in our neck of the woods even though we had to replace a bunch of engine harnesses on older Macks. On the MP7's we have they are all getting new harnesses and the oilpump updates, that have anything to do with it?

Edited by aw12345

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Thanks, will try the back in service tomorrow, if not will do the back to back regens.

I have seen the DEF pump loss of power code on about 5-6 different trucks now all with a milage between 200.000 to 300.000 miles. 1 2011 MP8 and the others are all 2010 MP7's.

Corrosion isn't a terribly big problem in our neck of the woods even though we had to replace a bunch of engine harnesses on older Macks. On the MP7's we have they are all getting new harnesses and the oilpump updates, that have anything to do with it?

I've replaced a few def pump harnesses because of an open in the harness. The harness were poorly secured.

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HAVE A 2015 MP7 THAT LOST ITS DEF UNIT PRIME, lm thinking its the def pump or is there an issue lm over looking

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