CAT 299D3 XE Code E695-3 & 2685-8

[ChidJ]

First things first: SN CAT0299DPBX901558

Was on a mulch job today, everything going fine, then all of a sudden I get these codes yelling at me.

695 - UNEXPECTED MOTOR SPEED DETECTION DISABLED DRIVE SPEED IS LIMITED UNTIL FAULT IS CORRECTED

2685 - LEFT DRIVE MOTOR SPEED SENSOR #1 ABNORMAL FREQUENCY PULSE WIDTH OR PERIOD

I then turn everything off, walk around the machine, check everything, nothing seems out of the ordinary. Fluids are fine, nothing dangling or dripping.

I get back in and go again and no codes initially and then they come up again. It runs normally apart from occasionally pulling to the right, like the right track momentarily hesitates. Hydraulic power isn't lapsing, just the track motor. I ran it for about 15 more minutes with it yelling at me constantly, code popping up then going away over and over.

Please and thank you in advance. I know this has been brought up before but I wasn't able to discern what the troubleshooting steps were.

Please help!

 

[Zewnten]

You need to lift the cab. Clean all the crap accumulated in the belly of the skid, carefully so as to not wrench the wiring and hydraulics. Then inspect the wires going to the solenoids on you drive motor. A lot of times the wires are damaged from debris pressing them into weird positions or the right solenoid has failed and needs replaced.

 

[ChidJ]

So I lifted the cab and did some looking. Couldn’t find anything abnormal. Here is a picture




However, as I did some following of lines I found this issue




Could this be causing those faults with some wiring there that has been compromised?

 

[Tyler d4c]

Very well could be if the wires are broke or rubbed. Replace the harness and mounting bracket and report back

 

[ChidJ]

On it

 

[Zewnten]

So I lifted the cab and did some looking. Couldn’t find anything abnormal. Here is a picture

View attachment 320196


However, as I did some following of lines I found this issue


View attachment 320197

Could this be causing those faults with some wiring there that has been compromised?

Good job keeping that clean. Too many let dirt and such accumulate and it leads to hydraulic leaks and electrical breaks.

 

[ChidJ]

Good job keeping that clean. Too many let dirt and such accumulate and it leads to hydraulic leaks and electrical breaks.

Thanks!

 

[Nige]

The E695 Event is a direct consequence of the 2685-8 Diagnostic Code.

There are two sensors built into a single common body on each side of the machine. The ECM requires a good signal from both of them to determine in which direction the machine is moving. If one sensor is bad then the unexpected motor speed detection function will not work.

Troubleshooting procedure attached. There is a truncated schematic contained within it but if you want a full one please ask.

 

[ChidJ]

Thank you, @Nige

 

[ChidJ]

Got it fixed. It was just the damaged wire. Bracket welded back together and wires spliced and we are back to work! Thank you again for all the help. This forum always comes through

 

[Innocent bystander]

Having same issue, but how do you get the code to clear?= Says need to see good signal from sensor before clearing but machine wont move due to code...??

 

[ChidJ]

When this happened to me, the machine would still move. It would just beep incessantly so you may have additional issues. That said, once I had the wire whole and plugged back into the sensor, the codes almost immediately went away.

Maybe a dumb question but have you turned it off, flipped the battery disconnect off, waited a while, then turned it back on? Are you confident the circuit is complete?

 

[Mr. Wrench]

What all codes do you have?

 

[Innocent bystander]

My tech has the codes but I believe 2687-8 and another similar for right drive sensor 1 and 2. I believe it has a pump drive issue, have no hydraulics/no travel, plan to pull charge pump off tomorrow to see if pump stack is spinning however it has no bolts mounting the charge pump on. TAW S#. Yes tried disconnecting bat.

 

[Simon C]

My tech has the codes but I believe 2687-8 and another similar for right drive sensor 1 and 2. I believe it has a pump drive issue, have no hydraulics/no travel, plan to pull charge pump off tomorrow to see if pump stack is spinning however it has no bolts mounting the charge pump on. TAW S#. Yes tried disconnecting bat.

How many hours on the unit? Does the fan spin when you start it up. Maybe post your serial number as I believe there was a split in TAW serial number.
Simon C

 

[Innocent bystander]

4400Hrs, customer claims coupler was replace one before. TAW01912. No fan thats what led me to suspect coupler, Confirmed this morning is coupler. Im on the fence pull pumps? or pull engine?? According to sis it says pull engine, I tend to go with that but looks like pumps might slightly be easier. IDK

 

[Nige]

Im on the fence pull pumps? or pull engine?? According to sis it says pull engine, I tend to go with that but looks like pumps might slightly be easier. IDK

It all depends on what you have for lifting gear. If you have the capacity then probably pull the engine is the easiest.

 

[Simon C]

4400Hrs, customer claims coupler was replace one before. TAW01912. No fan thats what led me to suspect coupler, Confirmed this morning is coupler. Im on the fence pull pumps? or pull engine?? According to sis it says pull engine, I tend to go with that but looks like pumps might slightly be easier. IDK

Some on this site have pulled the pumps after removing the divider in between from what I read. Need to have things very clean to do it that way or risk other bigger problems. Depends what you have for tooling as Nige said. If you don't have lifting power the pump end is an option.
Simon C