CAT 330LN Monitor and Controller error

[Liviu Popescu]

Hi all,

Old CAT 330Ln, SN 8CK00054. Today, when we stopped to swap the bucket with the hammer, after starting the machine it now has 2 alerts showing on the display: a controller error and a monitor error. Please see pic attached (bottom right of the panel - sun was shining so hard to take a picture). Also the engine speed dial is not working. The alarm is also sounding.

Is there something easy that we should check first or any common issues on these types of excavators before we have to go full blown diagnostics on this?

Thanks
Liviu

 

[Liviu Popescu]

Hi all,

I just want to give everybody an update on the situation - not sure what the interest is on a machine this old (it seems nobody replies to this thread) but I’ll go ahead anyway.

The problem is actually intermittent, yesterday it worked fine after I posted, today it’s done it again a few times.

I looked it up and there are 3 LED on the electronic controller mounted behind the fusebox. When it’s green everything is ok, when yellow comes on then the controller either has trouble communicating with the monitor or the monitor is not responding to the controller commands. If red then the controller is bad and needs repaired/replaced.

Sure enough, when there is no error the led is just green but as soon as the monitor throws up the 2 errors for the monitor and controller, it turns yellow.
What was different from yesterday was that when it threw the errors today the whole LCD was turned off, yesterday we had the gauges working.

We will check the harness tomorrow, I’m hoping for a bad fuse or bad earth or some sort of short in the 2 cables that communicate between the controller and monitor.

If anybody ever experienced this and knows any probable cause I would really appreciate the help - I’m sure you all worked on these machines before.

Liviu

 

[John C.]

It sounds like you have a handle on what needs to be done. It's been twenty or more years since that machine was new. The harness connectors and contact points will have corrosion all over the place. One thing I do when I see those kinds of problems is a shake test around each connector. That the problem is intermittent, tends to make me think the display and processor are OK. Good Luck!

 

[Nige]

There is a member on HEF by the name of @anuradha who appears to be have a lot of experience on these systems.
If he does not post in this thread I would suggest that you contact him by PM.

 

[Nige]

Before making the comment above I should've checked the location of @anuradha.
He is located in Sri Lanka which unfortunately is experiencing a lot of political upheaval at the moment. He might just have other more important things on his mind right now.
https://www.bbc.com/news/world-asia-61417972

 

[Liviu Popescu]

Thanks for your help Nige. Hope everything is ok there the excavator was fine today, we’ll try and have a look on Saturday.

 

[anuradha]

Hi,

I looked at this thread after seeing Nige sir's PM.

As explained above, 02 alert indicators on the monitor, yellow led on the controller represent the communication error between controller & monitor. First thing should check is the wiring ( 02 data lines between monitor & controller ) & relevent connectors. Check the connectors for corrosion. There are about 04 connectors to check including monitor connector and controller connectors along the data line. Spray some contact cleaners for connector insides if available. Check the 02 ground wires to the controller, whether it is providing good ground connection to the controller.

If all these wirings and connectors are good, then the controller or monitor faulty, or both the components are faulty.
As you said i assume that the engine rpm also couldn't control at that time using engine speed control dial knob. And you said that the alarm also sounded, then we can think that the controller is faulty. Because if the monitor is faulty and controller is good, there shouldn't be a problem for engine rpm control circuit.
If the controller is faulty what will happen is, this communication error and other issues will arise more frequently in the future and at some point this communication error will stay continuously.

So if the above mentioned wiring & connectors are all good, i suggest to remove the controller from the machine & carefully open the controller's top lid by removing 16 bolts around the controller's top lid.( be careful not to damage the rubber seal which is placed between the lid and the housing )

Inspect for any kind of visible damage or corrosion inside the controller. Inside there are 03 circuit boards parrelal to each other. On the top board there is a microprocessor, check its pins carefully as well.

If the controller's inside is good, then change an another controller if you have another machine and see what happens.

I think that this will be helpful to you some what.

Good luck !

 

[anuradha]

I have sent you the wiring diagram and checking procedures of wiring on this issue, please check your PM.

And here i have attached some pictures of the controller inside, those are not that good in quality but i think you can get an
idea by seeing those.

 

[Liviu Popescu]

Anuradha - thank you! I’ll respond in more detail tomorrow when I am near the machine but there was some conflicting info regarding the knob - it continued to work even when the monitor was out so I am ruling the controller at the moment.

 

[anuradha]

Anuradha - thank you! I’ll respond in more detail tomorrow when I am near the machine but there was some conflicting info regarding the knob - it continued to work even when the monitor was out so I am ruling the controller at the moment.

Hi,

As you said, though the egine speed dial worked properly still we can't think that the controller is good 100% . Because it is a seperate circuit from the communication line. In this case if the wirings are good, then either monitor or controller is faulty. So it is better if you can inspect the inside of the controller to get an idea.

If you have another machine in the site best thing is to do changing the controller or monitor to see what happens.

 

[Liviu Popescu]

Hi, I only have a 325BLN and a 950F series II, I have a crusher with a 3306 engine but the throttle on that is manual by wire.

 

[Liviu Popescu]

Hi All - update on the above situation.

we did not get a chance to verify the wiring today because we are now experiencing another issues. The left track is getting stuck. It seems to do it when you are pressing the pedal to the floor, if you go half-way then it does not get stuck. Also when it gets stuck, the swivel (rotation of the cabin) does not work. The cabin rotation works if you rev the engine higher and then reduce or if you move the joystick a few times.

I have no idea if this is related to the monitor/controller issues we are having. On this subject - it hasn't done it since I posted which is strange. Anyway when the track is blocked the controller LED is still green so not sure again if they are related.

We had issues before where if you extended the boom and stick to the max it would bog down the engine and was releasing a lot of black smoke but for the past 2 months it hasn't done that ( it did it quite frequently last year).

Any thoughts on what it could be? Please see video below of how it reacts. The right track works fine. I thought it might be an electrical issue but it has no pressure sensors on the track valves underneath the pedals.

Thanks
Liviu

 

[John C.]

That give me the impression of something broken or very loose inside the final drive itself. Were it mine, I would probably remove the cover on the final, or at least drain the fluid looking for shiny things in the oil.

 

[Liviu Popescu]

Hi John, would that cause the swing to stop working though?

 

[John C.]

You have an old machine likely with lots of worn internal parts. It is likely you have multiple problems. The gear side of the final drive is not connected to the hydraulic system. However the hydraulic motor is connected to the swing motor by a case drain. Damage in the travel hydraulic motor might be able to enter the swing hydraulic motor through that case drain. I would suggest pulling the case drain and return hydraulic filters and check for brass or steel particles caught in the filters. If you find contamination, you are likely going to need to remove some components for inspection and possible repairs.

 

[jrangel78]

I have sent you the wiring diagram and checking procedures of wiring on this issue, please check your PM.

And here i have attached some pictures of the controller inside, those are not that good in quality but i think you can get an
idea by seeing those.
good evening ... recently I just posted a comment about a problem I have with a cat 312A excavator prefix 7dk that does not indicate coolant temperature hydraulic oil temperature nor fuel level I am thinking about damage to the ECM controller and it is the same that appears in this post could you provide me if you have the schematics of the board of that ECM controller to test the components

 

[Liviu Popescu]

Hi all, they are going to look at the oil today hopefully - grasping straws a bit but if you look at min 2:52, when it swings left right, the track motor seems to want to move forward backwards. Could be nothing or something.

I've found an issue with this but it's unlikely this information that came out in 1994 is still applicable as it worked ok for 28 years. It's to do with negative flow control... which I don't particularly understand but am making an effort by reading as much as I can on it.

 

[Liviu Popescu]

Hi all, removed the oil from the final drive, there were no metallic shavings or anything in it, however the colour was of a grey-ish nature. We pulled a little out of the other side and it was black (in the white cup). The oil was changed this winter and the machine doesn’t have more than 250-300 hours since we changed it.

 

[John C.]

Negative flow is a system that shuts off the pump flow when there is no demand for oil. The main valve spools are all open center with a parallel passage. Oil goes through the valve and stops at the bottom. There is an orifice at that point which is connected to a hose that goes to the pump. When nothing is used that pressure is high and signals the pump to go to minimum flow. When a spool is shifted that pressure drops and the pump strokes up.
Hope that helps.

 

[Liviu Popescu]

Hi John - thanks for the explanation. Do you know if we can remove the cover of the final drive (the one with a lot of screws) to see what's inside without removing the track, final drive from the machine? Or would that not work. We are behind with our production and we need this excavator as it's the one which has the hammer so we're trying to figure out how to diagnose the issue while being able to work slowly with the machine while the parts arrive. Thank you!