DEF tank sensor

W

Wine Country

Active member
Mercedes of Lynwood WA is quoting 3k to replace the tank. The sensor reads no DEF. I have always filled it after trips. 55 k miles. 15 3500, Winnebago View.
 
Kajtek1

Kajtek1

1922 Ford T. No OBD
The tank is welded and if level sensor is bad, it makes for costly replacement.
But I would make sure it is not just the sensor fooling.
Did you top-off the tank?
The ultrasonic sensor need air gap on the top to read. When you top it off, it will not read, while the module will deduct calculated use from last measured level.
Meaning if you top it off at low DEF level, after some driving you still have tank almost full, when the gauge reads 0.
 
Nic7320

Nic7320

Solera 24S on a 2011 NCV3 chassis
This is ridiculous. Shame on Bosch and Mercedes to engineer a high failure item that can't be serviced.

Anyone know what kind of sensor this is? (Ultrasonic, optical, capacitive, other? It can't be resistive since it's in highly conductive and corrosive DEF).

The reason I ask is you might be able to fool your ECU to think the tank is full by forcing the circuit to the same state as the sensor did. But that requires some hacking.

Then to see the DEF level, you can use an external ultrasonic or capacitive sensor like the aftermarket sensors for RV fresh/gray/black water tanks. Those that stick to the outside of the tank with adhesive (why didn't MB do this?) and would be a much more affordable way to show you the tank level.

Another option might be to convert it to the older style DEF tank that was mounted on the frame rail (early 2010's) Those were in an access panel behind the RV door, and were bigger than the tanks they used later up front. They had a replacable DEF module that drops into the top of the tank, and a separate DEF pump mounted on top of the module.

The DEF module itself has a filter, heating element and the level sending unit. The Bosch part used to be on Amazon for about $200, but that was five years ago. I don't see them now, so you're back at the mercy of a MB parts distributor.

This idea assumes those parts are even available. If not, then were all in trouble down the road.

Anyone know of any Sprinter graveyards that might have these older DEF tanks?
 
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D

dharmasprint

Well-known member
Nic7320 said:
This is ridiculous. Shame on Bosch and Mercedes to engineer a high failure item that can't be serviced.

Anyone know what kind of sensor this is? (Ultrasonic, optical, capacitive, other? It can't be resistive since it's in highly conductive and corrosive DEF).

The reason I ask is you might be able to fool your ECU to think the tank is full by forcing the circuit to the same state as the sensor did. But that requires some hacking.

Then to see the DEF level, you can use an external ultrasonic or capacitive sensor like the aftermarket sensors for RV fresh/gray/black water tanks. Those that stick to the outside of the tank with adhesive (why didn't MB do this?) and would be a much more affordable way to show you the tank level.

Another option might be to convert it to the older style DEF tank that was mounted on the frame rail (early 2010's) Those were in an access panel behind the RV door, and were bigger than the later tanks up front. They had a replacable DEF module that drops into the top of the tank, and a separate DEF pump mounted on top of the module.

The DEF module itself has a filter, heating element and the level sending unit. The Bosch part used to be on Amazon for about $200, but that was five years ago. I don't see them now, so you're be back at the mercy of a MB parts distributor.

This idea assumes those parts are even available. If not, then were all in trouble down the road.

Anyone know of any Sprinter graveyards that might have these older DEF tanks?
Click to expand...
I've looked at a number of different wrecking yards and seldom if ever have I seen any MB sprinters of any vintage.

I do have a 2011 that I have started scavenging parts from but I purchased it whole.
 
W

Wine Country

Active member
I always kept DEF top up. I read years ago that you did not to get it low to cause issues with the sensor. I filled it up two gallons before I drove to MT from Seattle. I got the check Def without the eng light per the manual. No concern but I did fill two Liters when got fuel.
I did the right thing, it’s a Class C motor home. 99% of the miles are road, freeways. Little stop and go.
OK I got the countdown and took it in to Mercedes Lynwood WA. They are a Sprinter shop, the car part is up the road.
Mercedes/ Bosh design the DEF tank to be a replacement part ? OK but why so much money? 3 grand to keep the exhaust clean is not correct.
.
 
W

Wine Country

Active member
What I did was not let it run past halfway. I would two gallons after driving many miles. No gauge I would buy a container and fill it with some left over. No small additions except for the small amount last week after the note on Def.
 
I

irvingj

2015 RT SS Agile (3.0L)
It might have something to do with the cab/chassis truck that the View uses. I'd at least get a second opinion.

Also: As far as I know, 2015 models did NOT use the newer DEF level system later models use. Mine, also a 2015 but a 2500 chassis, does not have a "how much DEF is there" gauge, only a warning if it's low. I did get a "Check DEF" along with count-down the 2nd year we had it, which was traced to faulty (older V.2) NOx sensors. Replaced under warranty, no problems since, other than one of my own making. Currently 65K miles.
 
Mein Sprinter

Mein Sprinter

Known member
irvingj said:
It might have something to do with the cab/chassis truck that the View uses. I'd at least get a second opinion.

Also: As far as I know, 2015 models did NOT use the newer DEF level system later models use. Mine, also a 2015 but a 2500 chassis, does not have a "how much DEF is there" gauge, only a warning if it's low. I did get a "Check DEF" along with count-down the 2nd year we had it, which was traced to faulty (older V.2) NOx sensors. Replaced under warranty, no problems since, other than one of my own making. Currently 65K miles.
Click to expand...
Correct irvingj: Our 2010 also does NOT have a DEF sensor, according to Linear Logic, maker of ScanGauge III; only a warning display. Currently at 193, 234 miles.

Cheers...
 
Kajtek1

Kajtek1

1922 Ford T. No OBD
I tried JY in Sacramento few years ago.
The only Sprinter they had on the yard barely had some sheet metal left.
On other hand, lot of "recycling" JY have the prices, that with some internet search I can match, or get close with new parts.
But the truth is, that when we do have 'DEF tank autopsy" for vans on this forum, I did not see 1 for C&C models.
Cars do have tanks with heaters and level gauges who can be replaced separately without 4-digits price.
 
P

Pchild

New member
Wine Country said:
I always kept DEF top up. I read years ago that you did not to get it low to cause issues with the sensor. I filled it up two gallons before I drove to MT from Seattle. I got the check Def without the eng light per the manual. No concern but I did fill two Liters when got fuel.
I did the right thing, it’s a Class C motor home. 99% of the miles are road, freeways. Little stop and go.
OK I got the countdown and took it in to Mercedes Lynwood WA. They are a Sprinter shop, the car part is up the road.
Mercedes/ Bosh design the DEF tank to be a replacement part ? OK but why so much money? 3 grand to keep the exhaust clean is not correct.
.
Click to expand...
I recommend you check with Stones Sprinter service in Fremont. Over the years I have found them to be knowledgeable and straight shooters. Good guys.
 
Kajtek1

Kajtek1

1922 Ford T. No OBD
I banked $14,000 doing 4 AEM, but I am not in hurry to spend them. :cool:
I mean I spend them already, but not on cars.
What I am trying to figure out here is if you had bad gauge, or was it operator error.
 
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