2016 Cat 299D2 XHP Rebuilt from Burnout - Aux Lines Not Pressurizing

[Quantum]

Y'all may remember my project from here. I've almost finished rebuilding a 299D2 after buying it as a burnout from a junqueyard.

But I have not been able to figure out what's wrong with Aux 1 & 2 lines running down the arm. I have a grapple on the machine which just won't grapple. It uses the two smaller connections, Aux 1 & 2.

It appears that Aux 1 is supposed to pressurize to open the jaws, and Aux 2 is supposed to pressurize to close, but I'm getting zero pressure in each, as evidenced by loosening the lines at the cylinders.

So these Aux lines trace back to the implement control on the bulkhead and are controlled by two solenoids. I thought at first that maybe it just needs primed, but then, everything else run by the implement controller is working. (arms lift, tilt)

So I put pins through the wires going to the solenoids and connected a multimeter. The solenoids are run by PWM (pulse-width modulation) so I set the meter to AC voltage. When pulling the right joystick thumbwheel I get 6vAC on Aux1, which doesn't seem like enough. When pushing the thumbwheel I get only microvolts on Aux2, effectively nothing.

Using the prints to trace back the wiring it seems that Aux 1 & 2 signals come direct from the ECM! How can the ECM provide enough current? Well apparently it must.

So I decided that this must be a calibration issue, as I remembered going through current calibrations for the lift and tilt. I ran ET, and the current min and max settings (which I'd downloaded in this serial#'s factory setting .xml file and loaded to the ECM) did not seem out of line. But I set max higher on Aux1 & 2 to 1.2 amps, a bit high, and min current higher to .8 amps. Still did not work the grapple. Then I set max on both to 1.5 amps and min to 1 amp, way high. Still no action.

Well that blew my last theory out of the water.

Has anyone seen this behavior before?

 

[Vetech63]

Post a pic of your wiring diagram. It sounds like you have no input signals.

 

[Quantum]

Ok here's the complete schematic:
https://quantum-equities.com/Schematic-299D2_XHP.pdf
Vol 1 is the first two pages, and Vol 2 the second two.

Here's my analysis of the A1 and A2 circuits:

See, just about direct from the ECM to the solenoids. I thought maybe I'd gotten the solenoid connectors on the wrong solenoids, but the wire colors are right.

The other wires on Connector 6 all have to do with control of lift and tilt which is working correctly, so that ought to be good. One thing I haven't thought to check yet is the thumbwheel circuit.

 

[Quantum]

Hmm, there is a whole 'nother line of inquiry that I've missed -- the control circuit. Analysis:

The roller power and return are just +8vDC, which is the power supplied to all sensors by the ECM, so no need to trace this out. Although I will test to make sure it's at the joystick.

The thumb roller signal is another story. It claims to be PWM, but who's doing the PWMing? It could only be the ECM as this requires electronics. Unless there's a basic circuit in the handle? That would explain the need for power.

So the prints and their cartoons only show this circuit going through Connector 15, which passes into the cab from the outside, toward the bottom. I know for derned sure that there's another connector in the right console, because it was the cause of another horrific problem I had a couple months ago. Highly suspicious.

I'll crack it open and make it talk this evening.

 

[Quantum]

Last night I did some careful testing.

I started on the wiring from the joystick. I put pins through the yellow and white wires (+8vDC and return) and got screwy readings. Then I noticed that the wire colors from the joystick bear no relation to colors in the harness it connects to! Further, the wires in the harness it connects to actually have the circuit numbers printed on them so I could confirm that yellow, white, and green were the ones I was interested in,

Putting pins through yellow and white, indeed 7.9vDC, just as God intended. Now, measuring green and white for AC I found 3.8v with the thumbswitch centered, and 4.3v whether the switch is pulled up OR down. Well this doesn't make sense for a PWM signal. The pulse width is supposed to vary to different degrees depending on how far the switch is pulled and in which direction. So I switched the meter to DC. Median reading is 3.6vDC. Pushing the switch up it goes to 1.48v and pulling it down results in 5.8v. Well this makes alot more sense than AC. The machine would know from this how to operate the grapple. I don't know why it behaves this way except maybe the PWM signal causes a 'heating' voltage (RMS) in DC that's sensible to read.

Well it's a mystery why the joystick wires are so different from those it plugs in to which are confirmed correct. Could Cat have sold me the wrong joystick? The only part# on it is not a Cat number -- 221173. The real part# is 273-9104. It seems to be behaving correctly, although I don't know that my readings are actually correct.

So I moved on to the implement controller. I put pins through the wires on the Aux1 solenoid, started the machine, and tried the thumbwheel. Zero volts AC centered, and about 34 millivolts up or down. Zero volts DC no matter what. Same on the wires for the Aux2 solenoid.

So the control signals should be going directly to the ECM, and directly from the ECM to the solenoids. It's clear now why there's no hydraulic pressure... there's no solenoid voltage. They're obeying what they're told -- nothing.

But why would this be? Could the joystick be the wrong one? Could the ECM be bad?

 

[Quantum]

The local Cat dealer confirms that the tag on the joystick should be 221173, so it is the right one.

So it looks like the ECM is bad,

 

[BigWrench55]

I have ran into a similar problem. Except for that I couldn't get the high flow to work. Had to jumper two wires at the cannon plug near the auxiliary connector. Apparently all the new cat skidsteers have a harness on there attachments. And two of those wires tell the ecm that something is connected. Then the ecm turns on the auxiliary hydraulics. I will look to see if I can get you that information.

 

[BigWrench55]

Scratch that. That is for the high flow circuit.
You will have to hook up ET and turn on the auxiliary hydraulic function. Haven't done one in a while so I can't be much help in telling you more. Good luck and I hope that will get you on the right track.

 

[Quantum]

Thanks Paul. I do have the high-flow jumper plug and have considered trying that. Right now just a blank cap is on it.

I have connected ET, and the only settings I can find are Calibrate current (which I've tried), Override Aux Solenoids which won't accept any values, and Calibrate Aux solenoids which fails with "Not supported". (as opposed to most of the other calibrations, which I've done) I even did the traction solenoid calibration... I didn't bother with the instructions, and the machine took off like a rocket until I stopped it. Turns out you have to jack the machine off the ground for that!

Are you saying that there's an ET setting to enable Aux? That would be a revelation, although I haven't seen it anywhere, and ostensibly I'm in Factory Mode. I'll look again tonight. Also I'll check the wire functions on the cannon plug. Maybe I need to jumper something just to get -any- aux.

 

[Quantum]

Tracing all the cannon plug wires, here is my result:

For those here who are not technical, it appears that there is no pin in the cannon plug to enable regular pressure. Only 'High' and 'Super-High'... although you do have to wonder if "High" is Cat's version of 'regular'.

No idea what 'C1', 'C2', 'C+', or 'C-' are supposed to be... There is no explanation so we are supposed to pick it up by osmosis? Or telepathy? Maybe Aux 3 & 4? Aux 7 & 8? It is a mystery for the ages.

Yes let's all use different terms in different places....

 

[BigWrench55]

If I remember correctly. You will find where to enable auxiliary hydraulic in the implant section of ET. it's been too long for me to remember.

 

[Vetech63]

I would suggest you call CAT and have them hook up their ET to it. I have been doing this for 30+ years and even I have to do it sometimes. How much time do you have in this already trying to make a diagnosis?

 

[Quantum]

Vetech63, the thing is I owe the local dealer $2,800 because we have a disagreement. I've spent $32,000 with them for parts to rebuild this machine, and because the SIS system is terrible there were a number of misordered parts. Abbreviated descriptions, non-pictured parts, not breaking out parts in an assembly, not being able to find many parts and so on.

I've returned all the misordered parts and have receipts, but they refuse to refund because these are 'non-returnable' parts. Well I'm sorry but it's not my fault, it's SIS. They want me to pay $4,200 but I only actually owe $2,800, the difference being the returned parts. And if I make a partial payment to what they want, the penalty is the same as if I make no payment. So I am better off this way and we are at an impasse.

They say no one else has $1,400 in returned parts. I pointed out that I am probably the first in the world to fully rebuild a Tier 4 299D2, which is quite a complex job and I've bought hundreds and hundreds of parts from them. Doesn't phase them. Too bad.

Recently they said if I pay the $2,800 I say I owe, they would 'consider' goodwilling the rest. Well of course this was a ruse. They aren't going to 'goodwill' anything. I busted them on this by saying if we can sign an agreement that $2,800 is payment of my account in full, I will be down there tomorrow with the cash. No response for 2 weeks. And notice they don't admit that these are returned parts... it's as if I kept and used them or broke them but am refusing to pay, to be 'goodwilled'. And they've never admitted the problems with SIS, even though I invited the manager to witness the parts guy trying to find a dust cap for the Aux lines... after 20 minutes he gave up and said he'd have to research it later.

These refusals to acknowledge clear truths, look like dishonesty to me, so we have to have things in writing. They are behaving like a car dealer, so I'll treat them like one. I've let them know that if they ding my credit it will be an automatic lawsuit (with Cat enjoined, since they're responsible for SIS) and we'll let a jury decide.

I know that once a year dealers get to return parts to Cat for reimbursement, no questions asked. They initially volunteered this to me, but now they deny it. Please. This means that if they accept my offer they are out zero, and even if they don't return the disputed parts to Cat they'll still sell them eventually. Still in factory packaging. So it seems to me that it's only a question of their pride. Well, that's a shame.

Anyway, the Cat dealer isn't in a mood to look at my machine. And with what I've learned and done I am probably more knowledgeable than most if not all of their techs, except on those common recurring issues. I do my day job(s) during the day and work on the Cat at night.

Paul's posts above are beginning to make more sense. I originally downloaded my machine's ECM config.xml and loaded it into the ECM. This set my machine up as it was from the factory, specifically for my serial#. But maybe they ship with Aux -off-, so as not to ship with aux lines full of fluid. And maybe turning Aux on is one of those things they do at the dealer prep before delivery. So tonight I'll look everywhere for that setting.

 

[DEMLONE70]

Serial number would help

 

[BigWrench55]

This is what happened to me. I was working on a 420 integrated tool carrier. Was told that the aux hydraulics never worked since it was new.i went through all the usual troubleshooting procedures and found that it was controlled through the ecm. I called my buddy at cat and he walked me through the steps on ET to turn that function on. Not all machines are configured the same way. And if the ecm doesn't know that it's set up for certain features then those are disabled until you tell it otherwise. That was 4-5 years ago. I wish that I could remember what the steps are to enable that function. The only thing I can remember for sure is that it was in the implement section. Good luck with that and good luck with your dealer.

 

[Quantum]

DEMLONE70 serial# is DX200946.

Went over the ECMs with a fine-toothed comb last night and can not find a setting to turn Aux on.

To see a pic full-size you should be able to just click it. Or right-click|View
Machine Config:

Implement Config:

Quick Coupling - I suspect this is the hydraulic implement locker, and I have electric so irrelevant.

Valve calibration currents - Aux is set as high as I dare.

There's an Aux Calibrate procedure, but it always fails as "not supported", on both valves.

Here's what the readings look like when I actuate the thumb roller.
Up:

Centered:

Down:

It's starting to look like I'm pretty much screwed on this. I have a project that I have to get the machine on next week. Maybe I have to rig up a 3-way toggle switch to manually send voltage to the solenoids. In-line resistor to limit the current to 1 amp @ 12v.

Ah, I'm not concerned about the dealer, especially if it's just a matter of their pride. I've told the parts guy about this problem and that I may need a warranty replacement ECM, and he's not responding. I also need a hydraulic filter (still cleaning out system gunk)... but there is more than one way to skin a Cat.

 

[DEMLONE70]

The tool config is set to one way
A grappel need to be set two way

 

[Quantum]

If that were the problem, wouldn't one side work? Neither does. But I'll try it tonight.

Also I'm concerned about that "Auxiliary Valve #1 Port A Switch Position: Disabled or not installed". Don't know whether that is a problem or not. Don't know what that could be.

 

[Vetech63]

I wish you would hurry the hell up and fix that dam thing! LOL

 

[Quantum]

lol, you and me both. But I gotta day job, magn.

Literally the last thing that doesn't work after the Aux lines is the A/C compressor. Its relay isn't getting the voltage to come on. Not a priority (yet). But I start a 5 house development next week and this Aux thing has become an emergency.

In another thread I described replacing the backup camera.