My MX5800 HST shut down randomly on me and would not restart. Found a blown ECU fuse. Replaced it and got a little more work out of it before it did the same exact thing. Limped her home replacing fuses along the way. I sprayed some fluid film on the speed control pedal. Didn’t help and the fuse keeps blowing. Twice it shut off as soon as i sat in the seat. Other times it shut off for seemingly no reason while driving. Thinking a short circuit somewhere, but that’s hard to believe. Anyone got an easier diagnosis?
Fault codes U0081, U0082, and U0083
- Thread starter Sberti
- Start date
North Idaho Wolfman
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Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
This is what I’ve found regarding the codes...
U0081 / 523548-2: CAN-KBT frame error
Behaviour during malfunction:
• Insufficient output
Detection item:
• CAN-KBT original frame error
DTC set preconditions:
• Battery voltage is normal
• Key switch turn OFF to ON
• Starter switch signal (ECU: B-
54 terminal) is not activated
• No error of "CAN2 Bus off"
DTC set parameter:
• CAN2 KBT frame error open circuit or short circuit
Engine warning light:
•ON
System action:
• Forced Idle (Accelerator = 0 %)
Recovery from error:
• Key switch turn OFF
U0082 / 523591-2: CAN CCVS (Parking SW and Vehicle Speed) frame error
Behaviour during malfunction:
•None
Detection item:
• CAN CCVS communication stopping
DTC set preconditions:
• Battery voltage is normal
• Starter switch signal (ECU: B-
54 terminal) is not activated
DTC set parameter:
• CAN CCVS frame time out error
Engine warning light:
•ON
System action:
• Parking SW = OFF, Vehicle speed = 0 [default value]
Recovery from error:
• Key switch turn OFF
9Y1200192CRS0839US0
U0083 / 523592-2: CAN CM1 (Regen SW) frame error
Behaviour during malfunction:
•None
Detection item:
• CAN CM1 communication stopping
DTC set preconditions:
• Battery voltage is normal
• Starter switch signal (ECU: B-
54 terminal) is not activated
DTC set parameter:
• CAN CM1 frame time out error
Engine warning light:
•ON
System action:
• Regeneration inhibit = ON, Parked regeneration switch = OFF [default value]
Recovery from error:
• Key switch turn OFF
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
From all the things the codes are stating, it's sounding like either a wiring fault, like shorted or chewed wires, and / or damage to the ECU.
Kind of where I thought it was going. Don’t think it’s a sensor at this point with the blown fuses. Guess I’ll have to pull the deck and see if there is an obvious short somewhere. May just bring this one to the dealer
GreensvilleJay
Well-known member
Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
yeah, CAN bus is a real PITA, overly complicated and easy to malfunction due to substandard wiring/connectors and/or LOUSY software. I've dealt with it,even designed products with it and hate it. Wife's car would not start or run/drive without physical key and dealer head tech drew a blank look,..I TOLD him what it was,got told 'no way', they FINALLY did what I told them to do and '''magically' problem went away.....
can "can' be a pain
it's a real simple system, physically but there are a lot of ways it can have issues and it doesn't take much to make issues
there are bulletins at the dealer that address how to check the can system for communication errors (basically any of the u codes).
you're looking at a potential wiring problem ecu problem corrosion problem component problem or any combination of any of the above
what is can system? Controller area network. It is used to reduce the physical size of the wiring harness. With the complexity of common rail injection, if you used a standard wiring system, with several wires for each component, you'd have a harness with 100+ wires in it JUST to control the engine by itself. With can line, you may have only 10, so it's cheaper to make, lighter, and "simpler". Think of can as a "party line" where several components can communicate along the same "line"
it's a real simple system, physically but there are a lot of ways it can have issues and it doesn't take much to make issues
there are bulletins at the dealer that address how to check the can system for communication errors (basically any of the u codes).
you're looking at a potential wiring problem ecu problem corrosion problem component problem or any combination of any of the above
what is can system? Controller area network. It is used to reduce the physical size of the wiring harness. With the complexity of common rail injection, if you used a standard wiring system, with several wires for each component, you'd have a harness with 100+ wires in it JUST to control the engine by itself. With can line, you may have only 10, so it's cheaper to make, lighter, and "simpler". Think of can as a "party line" where several components can communicate along the same "line"
I would check the switch under the seat if there is one. I am not a mechanic. I sometimes fix things and amaze myself. Good luck.
GreensvilleJay
Well-known member
Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
re: it's a real simple system,
well, not really. CAN is like an onion, comprised of several 'layers', a minor 'glitch' in any of which can bring down the system. The 'physical' layer( the wires and connectors) usually are the main reason why CAN stops things from working. Bad design of connectors, substandard wiring installations, improper/wrong dielectric grease, bad/missing terminations and grounds. These are just some sf the 'simple' things of just ONE layer that makes CAN a nightmare. At the other end is the 'computer', or rather computerS. CAN systems,typically will have 'distributed processing', meaning they couldn't get one computer to do all they needed, so they put several on the 'bus'. This alone is a friginn nightmare. getting 2 let alone NINE computers to 'play nice' on one pair of wires is , well, challenging, to say the least. I've tested CAN systems where the mere act of connecting the diagnostic computer in 'magically' makes the original problem disappear. Not having access to the 10s of 1,000s of lines of source code means you're guessing about what the 'simple' timing details are, what 'threasholds' are, what the setpoints are.
Fortunately most(not all) 'problems' are hardware BUT something as simple as a shorted com wire does kill the system unlike other comm systems that can still operate with such a fault.
well, not really. CAN is like an onion, comprised of several 'layers', a minor 'glitch' in any of which can bring down the system. The 'physical' layer( the wires and connectors) usually are the main reason why CAN stops things from working. Bad design of connectors, substandard wiring installations, improper/wrong dielectric grease, bad/missing terminations and grounds. These are just some sf the 'simple' things of just ONE layer that makes CAN a nightmare. At the other end is the 'computer', or rather computerS. CAN systems,typically will have 'distributed processing', meaning they couldn't get one computer to do all they needed, so they put several on the 'bus'. This alone is a friginn nightmare. getting 2 let alone NINE computers to 'play nice' on one pair of wires is , well, challenging, to say the least. I've tested CAN systems where the mere act of connecting the diagnostic computer in 'magically' makes the original problem disappear. Not having access to the 10s of 1,000s of lines of source code means you're guessing about what the 'simple' timing details are, what 'threasholds' are, what the setpoints are.
Fortunately most(not all) 'problems' are hardware BUT something as simple as a shorted com wire does kill the system unlike other comm systems that can still operate with such a fault.
UPDATE: Tractor has been with the dealer for 4 weeks now. They haven’t been able to figure out the problem. They did find a resistor on the CAN termination that was somehow unplugged and haven’t been able to duplicate the issue. They’ve tested all the wiring harnesses, sensors, etc, and everything tests out fine. We’re all at a loss at this point. Going to pick it up next week and see if the problem persists.
Well tractor is back and I’ve run it for several hours without issue. Only thing I can think of is maybe there was some corrosion on one of the wires connections. They said they cleaned the connections while they were testing them. So maybe that was the issue? I do not know
My L3901 has been throwing these and an E20 code, all while occasionally blowing the main ECU fuse, since 25 hours into ownership. I traced the E20 and blown fuses to wiring ripped off the brake position sensor. Terribly poor design. I unplugged the pigtail for the sensor and the E20 and fuse blowing has stopped, but the CAN bus errors are still displayed.
What-de-heck she still runs fine!
What-de-heck she still runs fine!
Had codes U081-U082-U083 codes after tractor quit and blew ECU fuse—Discovered the seat switch had shorted out—still have codes but tractor runs great—Eliminated the seat switch !!! Anybody find a way to clear these codes ????
GreensvilleJay
Well-known member
Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
CANbus is really,really 'picky' about needing GREAT grounds, GREAT +12, and GREAT 'network cabling and connections'. IDIOTS at local Nissan dealership (with walls plastered with diplomas' couldn't figure out the SIMPLE prob;em with wife's new ride. After 3-4 trips there they FINALLY did what I TOLD them to do....and 'magically' car has been fine since then. My silly, $5, homemade CANbus diagnostic 'puter' KNEW what was the problem,took all of 74 seconds....