New Holland L223

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.

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.

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

GaryHoff said: 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. Click to expand... 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.

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.

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.

try contacting tool_king, he's over that way

https://www.heavyequipmentforums.com/threads/nh-l220-interlocks-have-me-defeated.71899/#post-751943 He posted a picture of the diodes. They are in a less than desirable location. Is there power at pin 30 of the UCM relay? Is there power on pin 20 of CN1A UCM connector? What is the resistance from pin C to Pin D, on the 9 pin diagnostic connector? (located on the bottom right, near where your feet would rest)

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!!

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.

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.

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.

GaryHoff said: 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. Click to expand... I have a L223 2013 SN#NDM452918....I have a open relay ground. I could only find 1 diode. Do you think I have a ground fuse? If so, where do I find it and what does it look like?

Can someone send me or tell me where to find a image of a fuse box for my New Holland C238 with a serial # NEM47077? I can't find a manual for that serial number.

I have error code 9406 and want to check fuses. The machine runs but does not operate.

GaryHoff, I have a C232 newholland skidsteer too with that exact prob with no hydraulics and a 9406 code, i have tested everything you posted with no problems found, i would like to possibly test the UCM , can u text me at 306 948 9946 or if someone else knows these C232s in depth give me a message Thanks

Does anyone know how to test the UCM ?