CAT D6 dozer

This topic contains 15 replies and was last updated by joshua-melber 9 years 8 months ago
January 19th, 2012 6:50am
Hey everybody, man this seems like a cool website, its like a mechanic's facebook! Anyways one of my D6 Dozers has a problem. I bet it's something small and easy but i can't figure it out because I don't have the technical manual on hand. The hydraulic lock-out switch will not disengage and i cant figure out why. I checked all fuses and reset my circuit breakers. I thought it may be the pressure indicator for the seat but its not that either. Any advice is much appreciated.
January 21st, 2012 5:55pm
Hi Josh,

I have access to Cat svc. literature so maybe I can help you out. What is the serial number prefix on your machine? Usually those hydraulic lockout rocker switches on the dash console are backlight illuminated when activated. Is your's staying illuminated regardless of switch position? Have you tested the switch? Usually you can gently pry the switch assemly up from its opening in the dash panel and then separate the switch from the harness for testing. Pay attention to the orientation of the switch terminals when you unplug it from the harness. I can research this a little more once I have your serial number prefix. Are there any other problems with your machine that might be related?
January 22nd, 2012 12:19am
Here's some general info on the hydraulic lockout system operation. Usually the lockout rocker switch is used to send electrical power to a solenoid. The lockout solenoid is usually located on a pilot manifold. The pilot manifold on a D6 is sometimes in the service oompartment, infront of the hydraulic tank, on the RH side of the cab. Often, there will be an accumulator mounted on the pilot manifold. Caution! The presence of an accumulator means that the pilot system can be pressurized for a while after engine is shut down. If you decide to remove the pilot lockout solenoid for inspection, make sure the accumulator is discharged. If you're unsure of how to do this, ask someone knowledgable for help. The lockout solenoid needs to be energized in order for the pilot oil system to be unlocked so that you can use the hydraulics. When the electrical power to the solenoid is interrupted, either by the lockout switch or by a circuit fault, a spring inside the solenoid becomes dominant, and the solenoid plunger moves to achieve a locked mode, preventing the hydraulics from being actuated. One of my first diagnostic steps would be to measure electrical power at the lockout solenoid with the rocker switch in the unlock position. If there's no electrical power at the solenoid, perform electrical continuity checks on the lockout switch. If there is power at the lockout solenoid, suspect a mechanical failure of the solenoid. If you have an inductive amp clamp available, measuring the current to the solenoid can be helpful. If there is power at the solenoid, my next diagnostic step would be to plumb a pressure guage into the pilot oil systrem downstream from the lockout valve. Also measuring the solenoid coil's electrical resistance is recommended. If you have electrical power at the lockout solenoid and pilot pressure is zero downstream from the solenoid, the solenoid is faulty.

If this is an electronic machine, there may be a machine control module in the circuit. The lockout rocker switch will provide an input signal to the control module. The control module will output a signal to the pilot lockout solenoid to energize it. If this is an electronic machine, and you have diagnostic software available to you, check for fault codes and you would be able to monitor the lockout switch status parameter on the computer to verify that the lockout switch is operating correctly.

With the serial number prefix of your machine I will be able to provide more machine specific details to help with troubleshooting. Be safe.
January 22nd, 2012 4:06pm
Wow! I'm really impressed with your answers, Giles. Keep it up. I've just given you a click on the karma button.
January 23rd, 2012 10:52am
Hey thanks alot everybody! Im currently not at my shop now, but i will post the serial # tomorrow morning when i get there. As far as the switch goes, i did test it and the switch is fine, i even tried it on another identical dozer and it worked fine for that one. This machine is electronic, and does have an ECM, and is popping code (Electronic IMPL #2 Abnormal Updates) and there is another code about changing the operation mode as well. Im gonna be furious if it is something extremely simple because i originally troubleshot it the old fashioned way, i dropped all the plates underneath and tried lookin for a possible solenoid for the lockout, but nothing was marked for it. Some plugs were tagged, but couldnt find one for it, and like i said i dont even have a tech manual so ive really been shootin in the dark so far. To tell you the truth i thought i might get lucky, but i was wrong haha. I basically concluded its something with the ECM, but after reading the one comment from Giles about the possible solenoid it gives me new hope because it seems i may have been on the right track after all. One other thing to keep in mind,...this dozer has 25.6 easy lived hours on her, so it also makes me think the brain just might have had a small seizure haha, i couldnt imagine a mechanical faliure taking place, this thing doesnt even have a scratch on her.
January 23rd, 2012 9:40pm
my serial # is NCF00027, Model is D6KXL, and CONTR # is SPM500-01-D-0059-0014.
January 25th, 2012 3:37am
Your pilot shutoff solenoid will be located on the outlet manifold (end cover) of your main control valve bank that is located at the rear of the machine, in front of the ripper. The solenoid will have a green wire labeled E918 and an orange wire labeled H706. You will probably have to drop your belly pan guard to access the control valve bank. Fault codes associated with the lockout solenoid will be identified as CID 0358 on your machine control module. To help identify your outlet manifold, your pilot system accumulator is also attached to this outlet manifold. If you have easy access to your machine control module it might be easier to start testing there. From what I can tell, your machine control module is on the LH side of the machine under a flip up door. Not sure if its inside the cab. The E918 green circuit from the solenoid connects to ECM connector J2 at terminal 2 at the ECM. Circuit H706 orange connects to terminal 4 of the connector J2 at the ECM. ECM connector J2 will be the lower of the two connectors and is located at the opposite end of the ECM from the large rectangular bulge in the face of the ECM housing. If you disconnect your pilot lockout solenoid from the harness and measure the voltage across the two harness wires you should measure 2.5V being output from the ECM, with the bottom of the lockout switch pressed (hydraulics unlocked) and key on. This test will cause a 0358-03 fault code to set so you will have to clear it when done troubleshooting. Also, I noticed on the hydraulic schematic, that there was a pressure test tap connected to the outlet manifold for measuring pilot pressure downstream from the lockout solenoid. It might be a remote mounted pressure tap. If you have pressure guages this might be helpful. Good luck.
January 28th, 2012 9:25pm
can you check the system by monitor for codes or service code?

you can check it on the monitor or messenger display (if there is equipped)on the right site

If you have code "electronic IMPL control module abnormal update rate" you can check suply voltage,ground and data link.(maybe change SW version by et)If all is ok maybe the module is dead.Some machine had problem with modul.
January 31st, 2012 5:42am
i found that solenoid, i had to take everything our of the cab and the floorboards to get to it, and its still out of sight, but i could unplug it and verify the wire numbers. i replaced what the CAT guy that came thought was the secondary ECM and weirdly the switch and everything worked....for about 30 seconds. i tried using the blade, was lifting it off the ground and worked but then the lock turned on and that same code popped. Electronic IMPL Control 2 , Abnormal Update. 1558-9. i dont know where this 2nd ECM is because no manuals and the thing i thought it was is just for the ripper apparently.
January 31st, 2012 7:57pm
Hi I found this...The 300-3631 slave ECM control group may fail on certain D6K XL Track-Type Tractors. When the slave ECM control group fails, the blade angling function may not operate, implements do not work and/or implements work in only one direction. The following diagnostics code(s) may be logged:


1558 09

2143 09

The prefix of serial number is different from your but all machines are D6K.Maybe it help you.

I think (or I am afraid) that you will be to need et to diagnostic and replacing ECM slave.

The ecm 2 (slave) should be at the batteries compartment (on the top compartment).

We had same problem on D6K :-(

You can download some information:

Good luck :-)
February 2nd, 2012 12:35am
Yup those are the two codes im poppin'. Must be that slave ECM because I checked the other possibilities and it wasn't fun either but I wanted to make sure it wasnt something little like a bad harness or cut wires somewhere. Another tough one shootin' in the dark with no manuals. Thanks to everybody for all the great advice. I have a CAT rep coming out again so hopefully with my input from what i've learned from you all we can get this thing figured out quicker.
February 6th, 2012 11:21pm
Still haven't pinpointed the problem. The CAT tech thinks it is a problem somewhere with the data link and in the communication between the ECMs and the displays. Hopefully we can get some luck, he is coming out again sometime this week.
April 5th, 2012 3:21am
The problem was the Implement ECM needed to be updated with a new version of it. The first models had some problems (like i had) and they changed the entire ECM , that was the issue, its a shame CAT wasn't as aware about that because it could have saved myself and the CAT techs alot of time and effort.
April 17th, 2012 9:33pm
Hi..good news :-)..
October 8th, 2019 6:26pm
Hello Sonny, thank you for your inquiry. I am having a little trouble understanding your question, would you be able to rephrase it and send it in again?
March 14th, 2021 5:18pm

What does aut mean

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