'17 f250 DEF gauge

leon · January 2, 2018

I am trying to find information on the operation of this gauge, customer complains of gauge drops from full to @ half with no indication in between

it came in reading @ half and I put in 2 gallons and it is reading full. No codes in ipc. I'm not sure what type of level sender it is using, And I can't

seem to find what I'm looking for in the wsm or pced.

forddieseldoctor · January 2, 2018

I’m not sure where in the manual to look, but that may be normal. Remember they don’t use a traditional sender in the tank.

Keith Browning · January 2, 2018

The DEF level sensor is still a 3 bar sensor assembly indicating full, half and empty so it stands to reason the the "gauge" would behave this way. By the way the information is in the PCED under the Engine Control Components section.

leon · January 2, 2018

Ok guys, I was on this same thought path, but I was having a hard time making sure. It seems to reason to me

that its most likely the way it is going to operate. Keith I was looking through that section and...well I didn't see what I was looking for.

I'm sure you are right. thanks for the replies

forddieseldoctor · January 2, 2018

I was in that section of the pced also and all I found for def level was 3.2 stuff. But I didn’t spend a whole bunch of time on it either.

cbriggs · January 3, 2018

It is an ultrasonic sensor, sends a soundwave up through the def from the bottom and measures the return time of the signal to calculate the level of the fluid. They do not work if the fluid is frozen. We had a customer complaining of erratic def level readings after buying a new truck in December of last year. After a whole bunch of wasted time hotline gave us the operation description and told us not to replace anything as they were investigating the concern. In the mean time the customer was so worried about running out of def, he managed to get so much def in it that the filler pipe cracked when it froze. I cant seem to find it in the pced, i'll see if i can still access the hotline request.

Keith Browning · January 3, 2018

Where did you find that information? The PCED still describes it as a three level sensor... hmmm.

Chad_Kelsoe · January 3, 2018

"The reductant quality module provides the reductant tank level and reductant concentration to the PCM. The reductant quality module

incorporates an ultrasonic transducer and sensor assembly, located at the bottom of the reductant tank. The transducer produces timed

ultrasonic sound waves through the diesel exhaust fluid (DEF) and the sensor measures the return rate of the sound waves. As the DEF is

consumed, the liquid level lowers and the return speed increases. Additionally, the sensor monitors reductant concentration percentage by

calculating the speed of sound travel through the DEF and comparing it to an expected value. If this value is not met, the reductant is diluted

or contaminated. The reductant quality module is integral to the reductant tank assembly. "

Copied out of the PC/ED manual for a 17 F-250, description and operation, engine control components, Reductant Quality Module.

leon · January 3, 2018

Thanks, Chad. I think my problem on finding information on this was I was lookling for des.and op. of a level/heater assembly

For some reason I couldn't grasp the reductant quality module as being my target... I guess... I suppose its time to revisit the pced

and enjoy some quality reading.

Chad_Kelsoe · January 3, 2018

I had ran into one a few months ago that wouldn't take DEF like it was full, but the DEF level showed empty. After reading in the PC/ED manual, I decided to pull the tank to physically check the fluid level before I ordered a tank. That's when I found the fill hose had been wrapped around the vent housing at the factory, and with the tank and bed installed it pinched off the fill hose. I got that fixed and it took DEF normally. Other than that, I haven't seen any issues with DEF on the 17 and newer models.