inherited M6060 with DPF warning

jkrubi12

Well-known member

Equipment
B2601/LA435/QA54"/BH70/B8160box/BB1254/PFL1242/SGC0554/WC-68 Chipper
Sep 24, 2012
400
291
63
right coast
Diesel Exhaust Fluid (DEF) does not have anything to do with a Diesel Particulate Filter (DPF).

I believe that most (if not all) Kubota diesel's that have a DPF do not have or use DEF. I'm pretty sure that the only Kubota's that have a DPF are those that are sold in the USA with engines rated for more than 26 HP.

A DPF is generally the first 'filter' encountered in the exhaust system after the exhaust gasses leave the engine and enter the exhaust system. It's purpose is to collect unburned 'particulates' from the exhaust and 'reburn' them to clean the exhaust output. When a diesel engine equipped with a DPF enters a 'regeneration' phase (a 'regen') the Engine Control Unit (ECU) will force the engine to run at a determined RPM, usually a mid-to-high RPM, in order to heat up the filtering screen in the DPF and burn off the accumulated particulates and 'clean out' the DPF. This process is accomplished through high heat, time, and in some systems, the injection of raw fuel into the DPF.

DEF is used in conjunction with a specially designed catalytic converter to convert Nitrous Oxide (NOX) into water and nitrogen before the exhaust output leaves the exhaust system. This is accomplished by injecting DEF (65% urea / 35% water) into the catalytic converter which (in conjunction with the exhaust-heated catalyst) converts the NOX into water and nitrogen. This NOX catalytic converter is generally the last component in the exhaust system prior to the gasses exiting the system.

Both the DPF and the NOX catalyst usually have sensors attached to them which monitor the exhaust flow or content to ensure proper functioning of the component. In the case of the DPF the sensor's purpose is to monitor exhaust flow and determine when there is a flow restriction, indicating a build-up of particulates on the filtering screen inside the DPF. In this case the ECU would (or should) initiate a 'regen' to burn off the accumulated particulates. I would be interested to hear from Kubota tractor owners / users whose machines are equipped with manual regeneration switches and who have performed manually-initiated regenerations what actually occurs during a manually-initiated regeneration.

Additionally, the notification of a DPF problem could indicate the failure of a DPF sensor, in which case a repair would be considerably less expensive than a DPF replacement, possibly even user repairable.
 
Last edited:

Daren Todd

Well-known member
Lifetime Member

Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
May 18, 2014
10,201
6,715
113
Vilonia, Arkansas
Diesel Exhaust Fluid (DEF) does not have anything to do with a Diesel Particulate Filter (DPF).

I believe that most (if not all) Kubota diesel's that have a DPF do not have or use DEF. I'm pretty sure that the only Kubota's that have a DPF are those that are sold in the USA with engines rated for more than 26 HP.

A DPF is generally the first 'filter' encountered in the exhaust system after the exhaust gasses leave the engine and enter the exhaust system. It's purpose is to collect unburned 'particulates' from the exhaust and 'reburn' them to clean the exhaust output. When a diesel engine equipped with a DPF enters a 'regeneration' phase (a 'regen') the Engine Control Unit (ECU) will force the engine to run at a determined RPM, usually a mid-to-high RPM, in order to heat up the filtering screen in the DPF and burn off the accumulated particulates and 'clean out' the DPF. This process is accomplished through high heat, time, and in some systems, the injection of raw fuel into the DPF.

DEF is used in conjunction with a specially designed catalytic converter to convert Nitrous Oxide (NOX) into water and nitrogen before the exhaust output leaves the exhaust system. This is accomplished by injecting DEF (65% urea / 35% water) into the catalytic converter which (in conjunction with the exhaust-heated catalyst) converts the NOX into water and nitrogen. This NOX catalytic converter is generally the last component in the exhaust system prior to the gasses exiting the system.

Both the DPF and the NOX catalyst usually have sensors attached to them which monitor the exhaust flow or content to ensure proper functioning of the component. In the case of the DPF the sensor's purpose is to monitor exhaust flow and determine when there is a flow restriction, indicating a build-up of particulates on the filtering screen inside the DPF. In this case the ECU would (or should) initiate a 'regen' to burn off the accumulated particulates. I would be interested to hear from Kubota tractor owners / users whose machines are equipped with manual regeneration switches and who have performed manually-initiated regenerations what actually occurs during a manually-initiated regeneration.

Additionally, the notification of a DPF problem could indicate the failure of a DPF sensor, in which case a repair would be considerably less expensive that a DPF replacement, possibly even user repairable.
All modern diesels have a particulate filter. Whether they regen or not depends on horsepower.
 

RBsingl

Well-known member

Equipment
Kubota F 2690 72" rear discharge deck, Deere 955
Jul 1, 2022
409
428
63
Central IL
Any diesel equipped with a particulate filter MUST have regen capability or otherwise the filter would soon be loaded with particulate creating an unworkable exhaust restriction.

Diesel engines sold in the U.S. below the horsepower limit requirement for DPF along with higher power diesels in some applications are exempt from all or part of current Tier IV and do NOT have a particulate filter.

For example, I installed my 40 KW standby generator in 2018 to come in under the wire for Tier IV for that application. The Mitsubishi 3.3L turbo diesel has nothing in the exhaust stream but the turbocharger and a standard muffler. The only emissions item listed on it is the turbo.

My new delivered in January Kubota F2690 has a standard muffler, nothing more. The F3690 big brother has a DPF. Most higher horsepower applications will also have a DEF system to meet nox requirements.

Rodger
 
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