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New Holland L223

BigPetePL

New Member
Joined
Jun 10, 2018
Messages
4
Location
Long Island
Hi guys. I have 2012 skid steer, a little abused but worked pretty good before all hydraulics disappeared. When I seat down all controls on instrument cluster lights up, than nothing, no brake light no seat belt. After few seconds the yellow light with exclamation mark start blinking and beeping, code on display 9406. I can start the engine, but no operation light is blinking. I checked all fuses and relays. Seat and belt switches seems to be ok. Machine is now in north NJ. Highland Lakes 07422. Do you guys know any local mechanic or can help me out with repair process? Thank you for any advise.
 

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GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
9406 No CAN Communication From UCM/VCM

Try jumping your UCM relay (might be called EH control relay or K003 or VCM relay), pins 30 and 87 (might be labelled pins 1, and pin 4)
Please use a fused jumper wire, in case you contact the wrong pins together.

Also try jumping your Main power relay, pins 30 and 87 (might be labelled pins 1, and pin 4)

Once you get your machine started and moving: Check the harness on the left side under the cab. There is 4 diodes in the harness, sticking out on pigtails. They look like 2 wire bullet connectors from trailer wiring. They often get corroded, and then don't work. These diodes will prevent your relays from turning on, and will cause many issues. You can jump the wires together for testing purposes.

Depending on your machine, you may have fuses at the rear left of your machine, and also relays in the battery box. The fuses are ground fuses, for your relays, and controllers.

Need to know more about your machine to make any more advice. Is it a tier 3, tier 4a, or tier 4b? Serial number?

I'm not anywhere near your area, so cant help you that way. If you don't have a New Holland dealer in your area, you can always just use the Case dealer.
 
Last edited:

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
alpha fuses.jpg


Your actual fuse lay out may be a little different, depending on what serial number range your in. Refer to your operators manual.
 

BigPetePL

New Member
Joined
Jun 10, 2018
Messages
4
Location
Long Island
9406 No CAN Communication From VCM

Try jumping your UCM relay (might be called EH control relay or K003), pins 30 and 87 (might be labelled pins 1, and pin 4)
Please use a fused jumper wire, in case you contact the wrong pins together.

Also try jumping your Main power relay, pins 30 and 87 (might be labelled pins 1, and pin 4)

Once you get your machine started and moving: Check the harness on the left side under the cab. There is 4 diodes in the harness, sticking out on pigtails. They look like 2 wire bullet connectors from trailer wiring. They often get corroded, and then don't work. These diodes will prevent your relays from turning on, and will cause many issues. You can jump the wires together for testing purposes.

Depending on your machine, you may have fuses at the rear left of your machine, and also relays in the battery box. The fuses are ground fuses, for your relays, and controllers.

Need to know more about your machine to make any more advice. Is it a tier 3, tier 4a, or tier 4b? Serial number?

I'm not anywhere near your area, so cant help you that way. If you don't have a New Holland dealer in your area, you can always just use the Case dealer.
Thank you for your advice. Serial # NCM 452317. I’m not sure about tier, but it’s pretty basic version. I own it for couple of weeks only, so not really know a lot about the machine.
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
You have a Tier 3 machine

Machine will likely work after you removed the relays and jump the pins mentioned above.
You will most likely find the diodes in the harness are rotten off. The fuse box was also prone to melting, you may find a relay pin is melted or burnt.

Best of luck. Post some pictures of what you find please.
 

BigPetePL

New Member
Joined
Jun 10, 2018
Messages
4
Location
Long Island
I forgot to tell you that I did jump main power and EH control relays. No difference, the same reaction as with relays. Engine started, no lights on dash, than few seconds later blinking amber light and same code. I cleaned all fuses once again. Than I got to UCM to check the connections and diagnose the code 9406, as per service manual ( page 693). All connections, wires and resistance looks to be good. I didn't find any of the diodes underneath the cab. I'm just really confused with no lights on instrument cluster after I turn the key, no brake, no seat belt, no operation. I spent all day today on looking for the reason of that, no luck. I don't know what might cause that...Machine was fine last week, I parked it, shut off the engine and few days after all dead. Thank you for your help.
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic

BigPetePL

New Member
Joined
Jun 10, 2018
Messages
4
Location
Long Island
Gary, THANK YOU!!! You're the best!!! I checked everything, no success. Than I looked into the link you sent, Tom posted pictures and description where to find those diodes. I got them!! All falling apart, corrosion everywhere. They are located underneath the boom locking handle, between 2 thick harnesses, 4th is a little to the back, taped to harness. I cut the wires and used trailer extension harness to make new plug-ins. 200 miles trip around NJ to get 1 diode here and other there and here we go, all works as it should! Thank you guys a lot!!IMG_0129.jpg IMG_0121.jpg IMG_0122.jpg IMG_0126.jpg
 

GaryHoff

Senior Member
Joined
Feb 25, 2009
Messages
810
Location
Alberta, Canada
Occupation
Heavey Equipment Mechanic
Thanks for the follow up! Thank you for the pictures. I have fixed many machines with your issue, but have never taken the extra time to record my work. lol. Good to hear your issue is resolved.
 

CMC76

Active Member
Joined
Mar 16, 2019
Messages
42
Location
Wisconsin
These diodes are accessible only by lifting cab correct?
My machine has been sitting a few weeks, just got this same code. Only issue is its parked inside a shipping container and access will be a bear.
 

mofarms

New Member
Joined
Sep 22, 2023
Messages
2
Location
Missouri
Yes, you have to lift the machine to get to the harness under the cab. Most likely you’ll have to crack the hydraulic lines. Not all machines have the features that allow for the pilot control button method.

Also, it’s worth saying that you should check your fuse and relay box too. I have a C238 which does not appear to have any diodes (I dug into the harness and searched for hours). I solved my 9406 issue by removing my 10 relays and 6 fuses and spraying electrical contact cleaner in there thoroughly, then dried with shop air.
 
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