Cat 257B Aux hydraulics only work in one direction

[Nige]

While you are messing with the A1 & A2 solenoids do you have an external power source you can hook up to each of them in turn with the engine running to see if they work and the hydraulics load up.? Even better if you have an attachment that can be connected hydraulically to the machine.

The only problem I have right now is I can't find information regarding the operating voltage of the solenoids, so to be safe I wouldn't recommend applying any more than 6v to them, certainly not battery voltage.

 

[Tyler d4c]

Maybe worth a look at the continues flow switch perhaps the switch is stuck in the pressed position

 

[Nige]

Maybe worth a look at the continues flow switch perhaps the switch is stuck in the pressed position

Tyler makes a good point. Go to the LH handle and open up the 12-pin connector.
Check the continuity on Pins 11 & 12 for the Cont Flow switch as you press & release the button.

 

[Nige]

Continuing on from that........
When you finish testing the Continuous Flow switch, leave the 12-pin disconnected and measure the output between Pins 40, 42, & 58 of the AUX ECM and the input to the A1 & A2 solenoids like you did before. Do you see any change from the previous tests when the thumbwheel is rolled one way then the other.?

 

[CotterFCattle]

Continuing on from that........
When you finish testing the Continuous Flow switch, leave the 12-pin disconnected and measure the output between Pins 40, 42, & 58 of the AUX ECM and the input to the A1 & A2 solenoids like you did before. Do you see any change from the previous tests when the thumbwheel is rolled one way then the other.?

Ok so to test this I can have the 12 pin disconnected for both these tests? Or I need to probe from the back and leave them connected?

 

[CotterFCattle]

Potentially yes. while you are in there disconnecting A-C24 & A-C25 also test the resistance of the solenoid coils for A1 & A2. It should be 2.2 ± 0.2 ohms.

It's called the Aux Hyd Control ECM and the Part Number I see for it is 216-0658. There may be a newer Part Number than that and there also might be the opportunity for a Reman ECM which would have a Part Number something like 10Rxxxx or 20Rxxxx. You would have to ask your dealer Parts Dept. Before condemning an ECM it's worthwhile doing all the tests that can be thought up, and few more besides, mostly because of the cost.

I take it from your OP that the AUX function has never worked since you have owned the machine.?

Correct, the past owner told me it didn’t work and at the time I was not too concerned. He acted like it wasn’t worth fixing for him but wouldn’t say how much he looked into it.

 

[Nige]

Ok so to test this I can have the 12 pin disconnected for both these tests?

Correct.
1. The 12-pin connector on the LH joystick was dsconnected to confirm that the Continuous Flow push-button switch was working correctly.
2. Leave it disconnected, and turn the key switch ON.
3. Roll the thumbwheel to both extremes while backprobing Pins 40 & 42 then Pins 42 & 58 of the AUX ECM.
4. Repeat Step 3 but measure by backprobing at connectors A-C24 & A-C25 at the solenoid end of the circuit.
See if anything changes from what you posted previously........

"Between 40 and 42 it shows nothing in the center position. When I push the switch down it shows -2.65. When I release the button it does not return to 0. When I push the button up it returns to 0

Between 42 and 58 it shows 0 with the switch in the center position or up position. In the down position it shows a slight negative of -.029"

 

[Nige]

Did you measure the resistance of the A1 & A2 solenoid coils.?

 

[Nige]

It's called the Aux Hyd Control ECM and the Part Number I see for it is 216-0658. There may be a newer Part Number than that and there also might be the opportunity for a Reman ECM which would have a Part Number something like 10Rxxxx or 20Rxxxx.

Confirmed that 216-0658 is the latest current Part Number. The Reman Part Number is 10R-5613. But don't go condeming the ECM just yet.........

 

[Nige]

The only problem I have right now is I can't find information regarding the operating voltage of the solenoids, so to be safe I wouldn't recommend applying any more than 6v to them, certainly not battery voltage.

Cancel that. You can safely apply 12v direct to the coil in order to test them.

 

[CotterFCattle]

Ok I am beyond confused now. Here’s what I found tonight in following your directions:

Disconnect the 12 pin connection LH handle and test for continuity on pins 11 and 12. No continuity with the bottom left joystick button pushed or released. Suggests that switch is bad. I did however get a reading of 1.1 volts on those same two pins when I press the top right button. Seems strange?

checked voltages coming out of ecm with the above connector disconnected. There was no rhyme or reason to my readings, and rolling the thumb wheel either direction basically had no effect. Plugged the connector back in with the same effects. To the point where I started the machine expecting no function of the thumb wheel at all but acts exactly the same. What would make it be erratic?

I checked both solenoids and they both fall within your parameters to be good. I ran out of time to try putting power to them but will tomorrow. I should actually be able to make the function run with that correct?

What are your thoughts? I checked and rechecked and don’t understand what made my post ecm readings change.

 

[Nige]

Disconnect the 12 pin connection LH handle and test for continuity on pins 11 and 12. No continuity with the bottom left joystick button pushed or released.

Provided you were checking on the joystick side of the 12-pin connector rather than the machine side - Confirmed that the Continuous flow switch is not working. Bad news if you ever need it because, like the RH handle, the switch is not available separately.

How many buttons does your LH joystick have.?

I checked both solenoids and they both fall within your parameters to be good. I ran out of time to try putting power to them but will tomorrow. I should actually be able to make the function run with that correct?

If the coil resistance falls within specification then applying 12v to each of those solenoids in turn should confirm if the hydraulic side of the AUX function is working as intended. If you have an attachment to hook up to the machine so much the better.

 

[CotterFCattle]

Yes, I made sure to test on the side of the plug that would go up to the handle. This machine has 4 buttons left and two buttons and the thumb wheel on the right. Will that switch not working on the left handle affect the thumb wheel though?

Yes they tested good. The grapple is on, I will run it and put power off a battery to both the solenoids.

Any thoughts on all my early readings though?

 

[Nige]

Will that switch not working on the left handle affect the thumb wheel though?

No it will not, or at least as far as I know it will not. Based on Tyler's suggestion we wanted to make sure the pushbutton was not giving a signal to the ECM that it was permanently pressed. On your machine Continuous Flow on the AUX system (to save you having to hold the thumbwheel over all the time) is achieved using a combination of inputs from the thumbwheel and the CF pushbutton to engage/disengage. So if your CF pushbutton is non-operational then CF will not work.

The grapple is on, I will run it and put power off a battery to both the solenoids.

Good. Initially try powering each of the solenoids in turn with the key ON, engine OFF. You should hear them give a distnct "click" when you power/depower them. If you get that then move on to test them with the engine running. Do this with CARE because by applying power direct you are bypassing all the systems in the machine controls that are designed to keep the operator safe.

 

[CotterFCattle]

Sorry for the delay, I wasn’t able to work on it yesterday. Here’s where I’m at:

Took a 12 volt battery and energized both solenoids. One was working the other was not. I took the non working one apart and cleaned it up and that solenoid now works.

I started the machine and used my outside power to run the grapple both directions as it should.

Then I reconnected everything and tried it. Still only works one direction. Ironically the circuit that is dead is the same circuit that bad solenoid was on. I am going to test one more time to be sure but it still appears that I don’t have power out of the ecm to that one circuit.

Is there anything else I should be checking??

 

[Nige]

Is there anything else I should be checking??

A couple of things spring to mind.

1. With the solenoids in their original position swap the wiring between them and test. Does the problem move with the wiring or stay where it is.?

2. Switch the position of the solenoids leaving everything else original wiring-wise, then test again.

The results of that should give you an indication if you have bad wiring. You are rapidly exhausting all the possibilities leaving a failed ECM as the only one.

 

[CotterFCattle]

I am having trouble with the function that typically worked acting strange now, I am going to run jumper wires from the ecm to those two solenoids to make sure there isn’t a wire issue between the ecm and the solenoid. Sound like a good idea?

 

[Nige]

I am having trouble with the function that typically worked acting strange now, I am going to run jumper wires from the ecm to those two solenoids to make sure there isn’t a wire issue between the ecm and the solenoid. Sound like a good idea?

It does to me. That ECM is expensive and mis-diagnosing it as bad could be bad for your wallet, as wel las not fixing the problem.

 

[CotterFCattle]

Ok heres where we’re at:

I disconnected the connector at the ecm and used my 12 volt battery to pin 42 and 40, then 42 and 58. Both solenoids function properly so I have determined that the wiring from the ecm to the solenoids is functioning correctly.

I also retested and the wiring from the switch to the ecm is working. So unless there is something outside of that simple circuit which affects how the ecm performs….. the ecm is bad. Correct?

Now here’s a thought…. This machine is highly optioned with all the different auxiliary line options but all I foresee myself caring about is the main aux circuit to run a grapple and a post hole auger. Could I not take those three wires that run out of the 12 pin connector by the switch, and bypass the ecm with those three completely, just have them run directly to the solenoids? We would leave everything plugged in so the switch would still have power, we would just be eliminating the brain and having the switch power the solenoids directly.

I know this would keep things like the continuous flow switch from working, but at this point I don’t care. Is the amount of voltage carried by those wires enough to run the solenoids?

I believe pin 1 is the common wire that runs to both, and 2 and 3 would each go to a solenoid. Correct?

 

[CotterFCattle]

And yes I know this is not a fix anyone would probably recommend. I would like to do it in a way that I could easily restore it to factory and replace the ecm down the road but not have to spend $1200 or more right now. Feel free to tell me if I’m totally wrong.