Case TV380 Moves backwards on its own, STOP light lit up

[ElliottG]

Hi guys,

Today we had our 2013 Case TV380 skid steer randomly stop working on a job. The machine suddenly started moving backwards on its own, and I counteracted by pushing the joysticks forward. As soon as I did that, the machine seemed to error out and the STOP light lit up, as well as the hydraulic override light flashing.

If I raise the lap bar and put it back down, then push the operate button again, the machine does the same thing and tries to go backwards on its own for a split second, then errors out.

We had two codes coming up on the display:
4752
5512

EDIT: I ended up finding the codes online:
4752: Ground drive: Command plausibility check
5512: Bucket rollback/dump: Sensor implausible state

Does anyone by chance work at a dealer or has access to the service manual to tell me what these codes mean?

The lap bar and seat sensor seem to function fine, and the appropriate lights go on when you sit in the seat, and when you put the bar down.

The machine had this problem a while ago (years), but it went away after restarting the machine. This is the first time it's happened in a long time.

Anyone had this happen to them before? Any insight other than checking the wiring and sensors on the joysticks? I guess I'll start there...

Thanks,
Elliott

 

[GaryHoff]

4752 – Left Swashplate angle sensor - Implausible command, command does not match with swashplate angle
This could be caused by a few things, faulty swashplate sensors, miss adjusted sensor, or your pumps are out of center. This code will stop you from driving, and light up the stop light. From your description of it driving on its own first, you may have a out of center pump, or faulty pump controls.

A faulty joystick will have a "joynu" code come up.

If you immediately moved the joystick to reverse, (after hitting operate) then its likely that the machine wouldn't code out.

5512 - Bucket Valve Spool Sensor - Implausible State Sensor vs. Loader Bucket Command
This is usually from a sticking spool position sensor on the loader control valve. This will stop you from using the boom or bucket or aux functions.

Also, all the fault codes are listed in the operators manual.

 

[ElliottG]

4752 – Left Swashplate angle sensor - Implausible command, command does not match with swashplate angle
This could be caused by a few things, faulty swashplate sensors, miss adjusted sensor, or your pumps are out of center. This code will stop you from driving, and light up the stop light.

5512 - Bucket Valve Spool Sensor - Implausible State Sensor vs. Loader Bucket Command
This is usually from a sticking spool position sensor on the loader control valve. This will stop you from using the boom or bucket or aux functions.

Also, all the fault codes are listed in the operators manual.

Thanks Gary. I did end up getting the codes and buying the service manual. I'm afraid there is something wrong with this machine that could get expensive very quickly...maybe the ECU or another controller. We have removed one of the swash plate angle sensors to test it (not done yet), but it looks like it's in mint condition and none of the wires are broken.

I forgot to mention that now we are getting codes for BOTH swash plate angle sensors.

It doesn't make sense that there would be a problem with both sensors at the same time. Why would both of them go bad at the exact same moment? And also, the machine moves straight back, not as if one side is stuck on more than the other.

Sucks having a broken $50k machine sitting in your driveway...

 

[GaryHoff]

The swash plate angle sensors are fed by the same 5v power, so if you have a power issue, you may get faults for both.

You are going to have a hard time adjusting the swash plate angle sensors. You will need to use a multi-meter, to set the sensors. Back probe the connectors to do this. With the machine in neutral, you will need to see 2.5V at both pins 3 and 4. (+ or - 0.1V) You can test the sensor this way too, the voltage should change as you slowly rotate the sensor.

for both sensors:
Pin 1 - Ground (#1)
Pin 2 - reference voltage 5v (#1)
Pin 3 - Pump angle (#2)
Pin 4 - Pump angle (#1)
Pin 5 - Reference voltage 5V (#2)
Pin 6- Ground (#2)

Any changes if you change your pattern controls to H pattern vs ISO?
Your not getting any short to ground or short to power codes, so it makes me believe your sensors are out of adjustment. They can be finicky to adjust.

 

[ElliottG]

The swash plate angle sensors are fed by the same 5v power, so if you have a power issue, you may get faults for both.

You are going to have a hard time adjusting the swash plate angle sensors. You will need to use a multi-meter, to set the sensors. Back probe the connectors to do this. With the machine in neutral, you will need to see 2.5V at both pins 3 and 4. (+ or - 0.1V) You can test the sensor this way too, the voltage should change as you slowly rotate the sensor.

for both sensors:
Pin 1 - Ground (#1)
Pin 2 - reference voltage 5v (#1)
Pin 3 - Pump angle (#2)
Pin 4 - Pump angle (#1)
Pin 5 - Reference voltage 5V (#2)
Pin 6- Ground (#2)

Any changes if you change your pattern controls to H pattern vs ISO?

Thanks for the heads up. We were going to test it with 5v from a USB plug.

And no we tried changing to ISO but again, as soon as we hit the operate button, the machine moves straight back and then errors out after about 2 feet.

Someone who's worked on similar caterpillar machines said that the sensors get "magnetized" then start reading incorrectly... He said to clean them with a special contact cleaner... The case dealer said the same thing... To clean them.

They look perfectly clean to me... But the guy said you have to spray them to get them to "reset"... Sounds like bogus to me but I'm almost out of options here...

It almost doesn't even seem like the angle sensors at all... More like something else is telling the machine to move straight back. The codes just say that the machine direction of travel doesn't match the angle sensors, which is true... But why would the machine move back without any input at all? It's almost like the solenoids are getting energized right when you hit the operate button, thus putting the machine into reverse...

 

[GaryHoff]

The swash plate angle sensors are likely ok. I don't have much trouble with them, sometimes they just need a slight adjustment.

I don't really buy into the "spray to reset" theory. The swash plate angle sensors are basically just potentiometers of sorts.

Mark all the coils on the pump, and remove them. (Just unscrew the black cap, and slide the coil off, this way the computer still sees the coils are connected) If the machine still creeps back, then the pumps are out of center. If the machine doesn't creep back, then the computer is sending a wrong message out.

 

[ElliottG]

The swash plate angle sensors are likely ok. I don't have much trouble with them, sometimes they just need a slight adjustment.

I don't really buy into the "spray to reset" theory. The swash plate angle sensors are basically just potentiometers of sorts.

Mark all the coils on the pump, and remove them. (Just unscrew the black cap, and slide the coil off, this way the computer still sees the coils are connected) If the machine still creeps back, then the pumps are out of center. If the machine doesn't creep back, then the computer is sending a wrong message out.

Thanks Gary! That's a really good tip. We'll definitely need to try it.

We took the black caps off the end a few days ago but didn't see how to remove the part connected to the pump. You just pull them off? Are they one long piece and go into the pump? Or do the solenoids come out separately? Basically if I take them out then start the machine I'm guessing hydraulic fluid won't fly out of the holes?

https://www.loaderpartssource.com/tandem-drive-pump-solenoid-coil-to-replace-case-oem-84389760.html

Judging by the pics there, it looks like they screw off?

Also for adjusting the angle sensors, you say to do it with the machine in neutral. By that do you mean the machine running but not "operating"? Are you saying rotate them with the elongated bolt holes until the value reaches 2.5V? Will fluid pour out if the bolts aren't completely tight?

Thanks so much. Really appreciate your help.

 

[GaryHoff]

Yup, your looking at the right picture
https://www.loaderpartssource.com/tandem-drive-pump-solenoid-coil-to-replace-case-oem-84389760.html

The black plastic cap just unscrews off (shouldn't be much more than hand tight) Then the solenoid will slide off separately.


You can adjust the swash plate angle sensor with just the cluster power on, and the engine not running. You just need the 5v power into the sensor. You will have to back probe pin 3 and pin 4, and rotate the sensor until you read 2.5 volts in pin 3 and pin 4. For example, a reading of 2.4v in pin 3, and 2.6v in pin 4 would be normal or a reading of 2.6v in pin 3 and 2.4v in pin 4 would be normal. There will be minimal oil loss with the bolts loose, as the only pressure there is the head pressure from the hydraulic tank.

 

[ElliottG]

Yup, your looking at the right picture
https://www.loaderpartssource.com/tandem-drive-pump-solenoid-coil-to-replace-case-oem-84389760.html

The black plastic cap just unscrews off (shouldn't be much more than hand tight) Then the solenoid will slide off separately.


You can adjust the swash plate angle sensor with just the cluster power on, and the engine not running. You just need the 5v power into the sensor. You will have to back probe pin 3 and pin 4, and rotate the sensor until you read 2.5 volts in pin 3 and pin 4. For example, a reading of 2.4v in pin 3, and 2.6v in pin 4 would be normal or a reading of 2.6v in pin 3 and 2.4v in pin 4 would be normal. There will be minimal oil loss with the bolts loose, as the only pressure there is the head pressure from the hydraulic tank.

Did some more troubleshooting today...

Took the solenoids off like you mentioned Gary for the reverse on both sides from the pump and the machine stopped moving backwards...

Also opened up the main UCM box and it looks perfect inside, no water ingress or anything of the sort.

Not sure what to do next...joysticks? broken wires somewhere? Boo...

 

[bartelbe]

Replace the sensor, 2 possible causes ,sensor or wiring. sensor could very well be sending false position so ucm is energizing coils to try and center the swash plates. and honestly the sensor is cheaper and hell of a lot easier to change then the harness.

 

[ElliottG]

Replace the sensor, 2 possible causes ,sensor or wiring. sensor could very well be sending false position so ucm is energizing coils to try and center the swash plates. and honestly the sensor is cheaper and hell of a lot easier to change then the harness.

I would tend to agree with you, but why would I get codes for BOTH angle sensors at the same time, as well as a code for the bucket position sensor? I'm leaning more towards it being something with the joysticks now...

And unfortunately the sensors are about $1200 each here in Canada so changing them without being 100% sure would suck.

Also, could you explain a bit about how the sensors work in conjunction with the solenoids? I thought the sensors were just safeties for the UCM to shut down the machine if the pumps were going to self destruct.

I also thought the solenoids were just on/off and open the flow from the pump to the motors... Incorrect?

 

[bartelbe]

if was joysticks then 2 things should be also true, 1 joynu in display when trying to release parking brakes, and 2nd should be able to isolated the issue by changing the pattern from h to iso. Since your getting the code for both and the the bucket then checking the signals back to the ucm would be a good check, youll need to back probe the connector at the ucm do you have a schematic?

 

[ElliottG]

if was joysticks then 2 things should be also true, 1 joynu in display when trying to release parking brakes, and 2nd should be able to isolated the issue by changing the pattern from h to iso. Since your getting the code for both and the the bucket then checking the signals back to the ucm would be a good check, youll need to back probe the connector at the ucm do you have a schematic?

I have had JOYNU come up sometimes but not every time, might have been me pushing on a joystick while trying to hit operate.

Yes I have the factory service manual. Which pins and values should I be looking for exactly? I've already checked continuity for wires going to the sensors so I know no wires are broken on those. Just check the signals going back to UCM from the sensors and check the voltages?

Btw thanks a hell of a lot for your replies I'm really stuck here aside from brining it to the dealer and probably paying $5k to resolve this

 

[bartelbe]

You can check voltage at sensor connectors but If that was a issue you should get a different code. Gary posted above the pin locations at the sensors for the signals references. You should be able to trace these back to the ucm on you schmatics for which connector and what pins are the signals. Should see 2.5v for a neutral position.

 

[GaryHoff]

When you removed the reverse solenoids, did the machine throw any fault codes?
Did the machine travel forwards ok (with the reverse solenoids removed)

Were you able to center the swash plate sensors?

Since the machine stopped moving when you removed the reverse solenoids, this means the UCM is sending out a wrong signal to the reverse solenoids. Sorry to be the one to say this, but you will likely need the dealership to update your software, and calibrate the pumps and joysticks.

 

[ElliottG]

When you removed the reverse solenoids, did the machine throw any fault codes?
Did the machine travel forwards ok (with the reverse solenoids removed)

Were you able to center the swash plate sensors?

Since the machine stopped moving when you removed the reverse solenoids, this means the UCM is sending out a wrong signal to the reverse solenoids. Sorry to be the one to say this, but you will likely need the dealership to update your software, and calibrate the pumps and joysticks.

Hi Gary

I believe the machine was still throwing codes for the bucket spool valve. I'll have to double check that.

With the solenoids removed, the machine moved forward just fine like normal, didn't error out.

You're right. I was planning on taking it in to get the new software and calibrate the pumps/joysticks. I believe the machine is on a pretty old firmware.

I've also had this problem with the machine since we've gotten it, where the bucket dump is verrrrrrrrrry slow, until about the last 10%, where it speeds up quite a bit. Changing joystick sensitivities does nothing to help it. Another possible symptom of joysticks?

Gary or Bartelbe would you be able to explain how the EH system works exactly with regards to the pump solenoids and sensors?

1) Is it the actual angle sensors that tell the UCM to angle the swash plates more, or are they just there to confirm to the UCM where the swash plates are?

2) What do the solenoids on the top of the pump actually do? Do they not just open up the flow to the hoses that go to each motor, thus allowing the fluid to flow from the pump?

3) What part of the system actually makes the swash plates angle more or less? Is there an electrical component somewhere or is it a regular hydraulic actuated system like all other regular machines out there?

 

[GaryHoff]

1. The swash plate angle sensors only tell the UCM where the swash plate is. They are only used during calibration. and to verify neutral of the pumps.
2. The solenoids on top of the pumps are the servo control solenoids. When power is sent to them they proportionally send hydraulic pressure to the pump servos, which in turn will proportionally control the pump flow.
3. The servo is what controls the swash plate angle. More swash plate angle=more flow.

Hopefully this answers your questions, although its hydraulic and electrical components working together that make this system operate.

https://www.boschrexroth.com/ics/ca...log&m=DE&u=si&o=Desktop&p=p662687&language=EN

page 16 may be helpful.
https://md.boschrexroth.com/modules...18070A4798.borex-tc&sch=M&id=13050,20,1168828

 

[ElliottG]

Well just an update on this...machine has been at the dealer Since about December. They just called a week ago saying it was the ECU that needed to be changed...apparently the machine works, haven't gone to pick it up...they could only pass 50% of the cost under warranty.......Suffice it to say I think we'll get rid of this machine as soon as spring comes. Way too many things potentially to go wrong with it in times of need.

 

[GaryHoff]

Thanks for the status update. Its unfortunate that the dealership had taken so long to repair your issue, especially since most of the troubleshooting was done here.

Although your having second thoughts on the dependability of your machine, remember that all newer makes and models will have large amount of electronics, and will have similar potential for issues.

 

[ElliottG]

Thanks for the status update. Its unfortunate that the dealership had taken so long to repair your issue, especially since most of the troubleshooting was done here.

Although your having second thoughts on the dependability of your machine, remember that all newer makes and models will have large amount of electronics, and will have similar potential for issues.

You're definitely right about that, Gary. The idea now is to get an older, more mechanical machine. We had a 40XT and even though it wasn't as powerful as the 380, it was way more reliable. Anything bad to say about the 400 series machines? A 440CT maybe...how much electronics are on those? Are the joysticks swash plates or electronic like the 380?

Thanks for your help on this thread by the way.