Kybota L3901 cranks but won't start

C

Catmechanic75

New member
Nov 2, 2026
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MO
Kubota L3901 cranks but won't start. Replaced 12v electric fuel pump as it was not working. After replacing it, it was getting fuel all the way to 3rd fuel pump supplying fuel to common rail. Still won't start. Replaced SCV after checking that it was getting power with key on. Still cranks but won't start. Loosened line goin to 3rd fuel pump and had good fuel with key on. Loosened line going to common rail and no fuel when cranking. It did have a P0606 code along with U0081, U0082, U0083. I cleared the codes with the dash button procedure and no codes have returned after several attempts to start again. Could this possibly be a failed fuel supply pump? Any help would be greatly appreciated.

PS I have removed all the fuses and checked for corrosion and to verify they were all good. Also the electric fuel never shuts off when the key is on. And it doesn't sound like it builds pressure. I'm not sure if it's supposed to shut off when it builds pressure on this particular tractor. I'm just going off of how I've seen most electric fuel pumps operate on other equipment. Tractor has 935 hours.
 
Last edited:
TheOldHokie

TheOldHokie

Well-known member
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Equipment
L3901/LA525, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
windyridgefarm.us
Catmechanic75 said:
Kubota L3901 cranks but won't start. Replaced 12v electric fuel pump as it was not working. After replacing it, it was getting fuel all the way to 3rd fuel pump supplying fuel to common rail. Still won't start. Replaced SCV after checking that it was getting power with key on. Still cranks but won't start. Loosened line goin to 3rd fuel pump and had good fuel with key on. Loosened line going to common rail and no fuel when cranking. It did have a P0606 code along with U0081, U0082, U0083. I cleared the codes with the dash button procedure and no codes have returned after several attempts to start again. Could this possibly be a failed fuel supply pump? Any help would be greatly appreciated.

PS I have removed all the fuses and checked for corrosion and to verify they were all good. Also the electric fuel never shuts off when the key is on. And it doesn't sound like it builds pressure. I'm not sure if it's supposed to shut off when it builds pressure on this particular tractor. I'm just going off of how I've seen most electric fuel pumps operate on other equipment. Tractor has 935 hours.
Click to expand...
The search function is your friend. This is a familiar topic.

TSB-2023-035-E-R3

Issue: The engine may fail to start, and DTC code P0605 or P0606 may appear.

Solution: If DTC P0605 is present, replace the engine ECU with the updated engine ECU per the Workshop Manual and complete a manual DPF regeneration per the Diagnosis Manual.

If only DTC P0606 is present, update the ECU Software to the latest software and clear the DTC codes

Dan
 
C

Catmechanic75

New member
Nov 2, 2026
3
0
1
MO
TheOldHokie said:
The search function is your friend. This is a familiar topic.

TSB-2023-035-E-R3

Issue: The engine may fail to start, and DTC code P0605 or P0606 may appear.

Solution: If DTC P0605 is present, replace the engine ECU with the updated engine ECU per the Workshop Manual and complete a manual DPF regeneration per the Diagnosis Manual.

If only DTC P0606 is present, update the ECU Software to the latest software and clear the DTC codes

Dan
Click to expand...
I saw this. But nothing came back after I cleared them. And from what I read, one or both should have come back.
 
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