caterpillar 259D3

[Chains&Binders]

CAT0259DAW////CW917475

OK. So local CAT service is 3 weeks out or so. I'm the mechanic and figured I will give it a look. Cant hurt with an extended wait for Cat service so I pull the Event and diagnostic codes from screen inside machine.
2687-8 right drive motor speed sensor #1 abnormal
2688-8 right drive motor speed sensor #2 abnormal
3700-3 Loader Bucket Inclinometer voltage above normal

events are listed as E570-2 Unexpected right motor forward speed detected. Check sensor/wiring
E875-2 Low system voltage

so, i found good info on this forum for the codes with a schematic courtesy of Nige in a different thread. Test for 8 volts on harness under cab at plug , both sides. Good solid 8 volts. On a prayer i ordered the track speed sensor ( in stock ) and picked upFriday. Installed today.with it apart i was able to Load test the harness from the main harness to sensor. Used a headlamp and tested the integrity of the harness that runs through the body to back of final drive. checked that the reluctor ring was inrtact and tight. It was. I did not remove tracks and spin final driveto check if reluctor wheel was fully intact. since i had pulled undercarraige off pins i didnt want to run it etc. Read that machine needs to see tracks running off of ground in order to clear code or at the very least allow machine to function properly with a historical code? Not a CAT guru and dont know if they store inactive codes in history like trucks etc. So, after a minute or so after putting together and running forward off idle it locks me out with the E570-2 . Need some guidance if anyone has any insight. I guess before i throw in the towel i will test from the under cab harness to the ECM for circuit integrity/Continuity. No pin out at my disposal but I should be able to determine which opins are what, hopefully.

anyone seen anything from these newer 259'S with the ECM or an update for this problem? Hoping to get CAT software capabilities but were not there yet. dissapointing outcome for sure with many solved with a new sensor. Sensor harness is definitely solid as it can carry current to light a headlight bulb on both supply/return side and signal side. I appreciate any help. Maybe i can update if a can find no problem with harness between under cab plug and ECM. Less than 300 hours.

thank you for reading.

 

[Nige]

If you have both RH speed sensors giving Codes for FMI08 abnormal signal the cause is generally NOT the sensor. As you have seen the two speed sensors share a common body, power supply, and ground. So if you have eliminated the harness and installed a new sensor then it appears as though the problem could be inside the final drive. I assume you checked the integrity of both signal wires from the sensor right back to the ECM.?

When you checked for 8v were you using machine frame ground as "ground" or the ground wire in the sensor connector that returns back to the ECM.? You should be using the latter but lots of people think "ground is ground, wherever" which ain't necessarily the case with that stabilized 8v sensor supply.

 

[Chains&Binders]

Thanks Nige. Appreciate your input. So. oddly enough the two signals originate from a single sensor? i see in a previous schematic for this code posted shows 4 wires. a 8volt supply and a return on pins 1 and 2 then the pins 3 and pin 4 are signal #1 and signal #2. One sensor. ( 4 wire / 6 pin plug with 2 empty spaces at the sensor ) So i used a seperate battery with Terminal jumpers that fit properly and just did a basic load test on the harness as if it was on a bench. I did have a solid 8 volts when testing at the main harness plug at beginning of the sub harness for sensor Friday USING the power and return at the harness plug. As supplied by the ECM etc. I wonder if I screwed up now? The supply and return jumped with a voltmeter, key on read 8 volts. I really am getting rusty lately as ive been running througfh everything but electrical recently. I need to refresh my knowleadge i think. dont use it you lose it.

so the supply and return side is always 8 volts and the #1 and #2 signal wires are square waves if i scoped them? oddly it looks like one sensor provides 2 seperate signals and thats a different scenario then im used too. Heading home now to read up tonight. Had way too much to do this past weekend to think about it.

As I sit here now, i wonder if my schematic is solid? 2687-8 but these can change year to year.

I don't know for sure but it appears that the schematic does not show any junctions where a bad connection can occur. i doubt its a straight shot from that harness plug to ECM but i could be wrong.
If i pull that sensor back out and have someone run that track forward, and the reluctor wheel is fully intact then what else can go wrong in the drive? I'm not trained on Machinery in particular but i am an experienced mechanic. i UNPLUGGED AND PLUGGED THE ECM and no dice . Wiggled the harness around in a attempt to force a fault, no dice.

I appreciate you taking the time to brainstorm with me. Looks like i really should go through the test steps top to bottom

 

[Chains&Binders]

any chance that the test procedure from another thread is different than this particular machine? I left the dang schematic on my desk. So I cant compare if the trouble tree is any Can you use the PIN from this machine for some info ? Im going go take a look at the cost and possibility that I can download Cat software with my laptop and NEXIQ passthrough? Not sure

 

[Nige]

I'll send you an electrical schematic appropriate for your Serial Number. Keep an eye on your messages.

So. oddly enough the two signals originate from a single sensor?

That's not 100% correct. There are 2 separate sensors mounted within a common body basically so that if one sensor fails the machine doesn't come to a ginding halt. The 2 sensors share a common stabilized 8v power supply produced within the ECM and a common ground back to the same ECM (not to machine frame ground). Each sensor has its own signal wire back to the ECM. That explains the 4 wires in the connector.

so the supply and return side is always 8 volts and the #1 and #2 signal wires are square waves if i scoped them?

Yes indeedy. The manual speaks thusly........... "The motor speed sensors allow the ECM to determine the actual speed of the LH & RH hydraulic drive motors. Each sensor provides two square wave signals that are proportional to the speed of the motor. The signals are used to calculate the speed and direction of each motor. The sensors are powered by a regulated 8 VDC power supply produced within the Machine ECM."

Attached the testing procedures for 2687-8 and 2688-8.

 

[Chains&Binders]

THIS IS VERY HELPFUL! Just spent the last hour trying to get Service information with no luck. Clearly willing to pay and saw monthly and annual subscription options but I cant navigate it myself I guess. Might be me? We do have a CAT account with an assets list and related info but not able to access service files. In fact i have SIS 2.0 but cannott access service software files? Guess i will be in contact with my local dealer tomorrow.

I really appreciate the information today! I cant tell you how great it is that you help this community like you do. It may be a ridiculous question but is there anything I can do to help myself get hooked up with Cat service software files? Spinning my wheels tonight i feel like. Thank You!

 

[Nige]

In fact i have SIS 2.0 but cannot access service software files?

Only dealers can access service software (aka flash) files, because only dealer versions of Caterpillar Electronic Technician software have the capability to upload said files into machine ECMs.

Check your messages. Maybe we can solve this..........

 

[Chains&Binders]

OK.. I see . I was mistaking the service software for the service informastion etc. Not the files to update ECM parameters etc. I can see now how that makes sense. So a couple things I'd like to figure out is what I need to do to actually scan the ECM from the deutch pin inside fuse box and also have access to service data. going to take a look now at messages. Thank you

 

[Chains&Binders]

The local dealers are updating to a new system. Not really up to speed on what it is exactly but i did receive an email that there may be interruptions. Hopefully They can help get us ( the business ) in the right direction. We have enough machines that justify having service data and the ability to scan the data and pull codes. Even if I can grab Events and some diagnostics from the machine itself.

I have a call in to Foley Bear Cat today. Fingers crossed

 

[Nige]

So a couple things I'd like to figure out is what I need to do to actually scan the ECM from the deutch pin inside fuse box

You need Cat ET software and a Communication Adapter (hardware) to do that. It's a totally separate function to SIS.

I assume that your machine has the Advanced Display on the RH side panel and that's where you are reading the Diagnostic Codes.? TBH connecting ET is not really going to give you much more diagnostic capability than you already have on the machine. On your particular machine the only real use for ET would be to perform calibrations.

One sensor. ( 4 wire / 6 pin plug with 2 empty spaces at the sensor )

That indicates you have the latest 6-pin sensors. Each of the speed sensor assemblies (LH & RH) should have a jumper harness (not sure how long) to a 4-pin connector further back towards the ECM.
Between the sensors and the ECM is also CONN 6 (30-pin) located on Grid B-9 of Page 4 of the schematic. I would suggest that you pull it apart and inspect/clean it with aerosol contact cleaner.

 

[Chains&Binders]

update coming. Was not the sensor or sub harness after i replaced therm. Had voltage and continuity from main harness.

So CAT road service came out and after running lots of tests is suspicous of the Hydraulic pump. CAT has had a cyuple main harness issues, but after an overlay eliminating the main harness its still acting up. Swapped some solenoids, still acting up. joysticks are good. CAT is at a loss. Never had one with this issue. Its a 120 hour machine.

Couple pumps have had issues internally on these but different symptoms. The right side continues tracking after letting off controls. setting the event code 570-2 unexpected forward motor speed. Will update when i find out some more info. Its going to CAT facility later this week. So expect a delay on update. It appears to be a hydraulic issue as all electrical possibiliies have been addressed over a couple days.

Sorry I been slammed and this is the first time ive been at a computer this week.

 

[Chains&Binders]

Nige. I want to personally thank you for your input. I couldn't have even begun without your schematics. After the big changeover at CATERPILLAR and their system updates I hope to get CAT software in house.

 

[Nige]

Thanks for the update. When it is finally sorted please come back and give details of the final solution.

After the big changeover at CATERPILLAR and their system updates I hope to get CAT software in house.

I sent you a message offering help with getting up & running with Cat SIS2.0. You're welcome to pursue that option "offline" so to speak if you wish. SIS can be a bit daunting to the uninitiated but it isn't that hard once you get right down to it.

 

[Chains&Binders]

I really hope to have more time soon to focus on this Cat SIS 2.0 and CAT ET. I have found our assets list and poked around a little but no service manual access currently. Just maintenance and operation manuals. Possibly parts ordering but I prefer the pro’s for sure but I’ve pulled my own #’s on most other equipment like trucks etc.

To make it more clear, our machine is not safe at all. No reverse. When you attempt to steer it does very random intermittent movements on its own. Could barely put it on the trailer safely. Very touchy. Almost sketchy.
After CAT told me 3 weeks I dug in and listed the codes and events. Tried the sensor after load testing the sub harness with no issues. No dice. Then miraculously CAT shows up by end of week! In hindsight I would have shipped it straight to CAT had I known but it was interesting speaking with the CAT Tech through out his diagnosis. He replaced the sensor and sub harness AGAIN, but I get it. Have to be safe. Apparently these drives have some issues internally. Not in this case but if anyone comes across a sensor covered in metal flake when removed you have an issue. So next he ran an overlay eliminating the main harness. Again, CAT has some bulletins on these harnesses having some problems. Not in this case, but there are “ technical bulletins “ in the pipeline. Next, he swapped some solenoids on top of hydraulic pump, possibly forward/reverse or left/right ( I wasn’t shadowing him around since I personally hate that myself) and that changed absolutely nothing. Regardless of swapped harness configurations from side to side, moving solenoids around, the right side kept tracking once you released the joystick. It was very consistent with setting the event code 570-2. Forward motor unexpected movement.
So after checking joysticks data and running a log on it he wrapped it up. Was considering swapping hydraulic drive hoses from side to side at bottom of pump I believe but his boss said wrap it up and bring it in to shop. 2 days on a road call under warranty probably wasn’t the best case scenario but it’s a messed up issue.
These machines have goofy hydraulic line connections too.Pronounced WEO? instead of face seal.

So, apparently CAT has had a couple internal pump issues. Different symptoms but the internals have failed in a handful. I think that they will give us a report once they determine the cause. I will tell anyone that runs across this thread. This machine has erroneous movements regardless of joystick position. At idle it will continue to track and not in any manner that you can control instantly as you would be accustomed to. Nothing jarring, just kind of ghost movements is best I can describe it. I wouldn’t even attempt moving off idle unless I was in an open field! When I know more I will update 100%.

This was an attempt at clarifying my last post on a time crunch and lots of misspelling etc. So sort of a repost with more time to explain. Thanks Nige

 

[Chains&Binders]

Quick update. Caterpillar is replacing the hydraulic pump. 10k on a roll of dice. Tech tore the pump down and they don’t see any particular issue but after swapping the lines from pump to the opposite sides the problem followed. Swash plate / internal pump issue is all that was left. Remanufactured pump is on order.

 

[Acoals]

This machine is under warranty yet?