Does anybody know what causes the park brake light to flash and the machine not to drive? The machine had a busted pump drive coupling, it was changed and now I can get hydraulic pressures(main and pilot). The implement works (blade) but i get no drive. There are no active error codes, the wires and park brake solenoid are good, 8 ohm. When the machine is started and the park brakes switch is pressed the park brake light flashes but no drive. I would like to believe the seat switch is good as it works together with the light on the dash...I get off the seat and the light comes on. I'm stumped, any help would be appreciated. Thanks in advance.
Usual Cat question - Serial Number..? Do you have an Electrical Schematic..? Answer to the first question gets the second.
Sorry about that, D4K LGP Serial HRRR00370. I don't have a schematic, I traced wires the hard way.
I think I may have found something. From the System Operation for the Tractor regarding the Display/Indicators....... Parking Brake (14) - This indicator indicates that the parking brake is engaged (Solid Red) or that Neutral is INTERLOCKED (Flashing Red). So from the above it appears as though the ECM is receiving a signal from the directional control that shows that it is not in neutral, irrespective of the position of the control lever itself.
Ok, thanks, its a start. Can you please try sending the schematic again. I don't know the wires for the neutral switch. The machine starts when the lever is in neutral position and does not when in forward or reverse. On the dash i can get into the status of the various controls, for the drive lever the display shows 49% in neutral, and i think 78% and 12% or something like that in forward and reverse positions. I'll have to check back those on the machine.
Hi, Nige I made a mistake, the machine will start with the park brake engaged but will not start with park brake disengaged...This is how it should work i believe. The neutral switch might really be a problem as the machine starts with the drive lever in any position once the parking brake is engaged.
You are correct. Unless the Parking Brake switch is in the applied position the engine should not start. That may be how it's designed to work, the Operator Manual is not 100% clear. What I'm fairly sure of though, is that to make the machine actually move if the engine is started with the control "not in neutral" will require the steering/transmission control to be placed in neutral first, then release the park brake, then move the control back to the desired position (F or R). Give it a try and see how it works.
Good day all, on the menu on the dash there is a setting PBLO on/off, when I changed it to off the park brake light stopped flashing. I think it might be park brake lockout?? but who knows. The problem is...the machine is still not driving!!! No active errors, no warning light, no flashing lamp..nothing. The machine starts with the drive lever on any position once the park brake switch is off. If its in F and the machine is started you have to put it in N, take engage and disengage the park brake and the park brake lamp works as normal, Everything shows as normal but still no drive. The HYSTAT, park brake solenoids read about 7.1 ohm each...within spec The wires read less that 1ohm each, each wire is not shorted to ground or power, all pin connections show no signs of corrosion. Why you no drive?? Please help
Have you tested for hydraulic pressure at the powertrain test points..?
It shouldn't start with switch in drive position, but this is a different issue to your problem. I think it's most likely the Operator In Seat sensor that's stopping your brake disengaging, as I've had the exact same problem on a 6K. If you get the seat cushion up you'll be able to adjust/bipass/replace according to taste. Personally I wouldn't bipass the switch as you could put it in drive when leaving the cockpit with the engine running.
Nice to have that confirmed. I had assumed that it ought to be impossible to crank the engine without both the park brake being ON and the direction control in neutral.
Hey thanks for the replies. I tested the pressures and they are within spec except park brake. With the pb switch off or on there is 0 psi, when drive is engaged and pb disengaged, I get 370psi (same as charge pressure). I believe this operation is good as you don't want the machine with brakes off if its in neutral. Not sure if the pressure is acceptable. If the pb is released and drive is F or R I can power the pump solenoids and the machine moves (I can do this to get L and R motors to drive in both forward and reverse so hydraulics are good). Seat switch works fine, NC and NO good. Brake pedal NC and NO switch good. Still stumped! All switches and solenoids are within spec as per schematic wiring, each was tested from machine ecm and were good with no shorts to +B or Gnd. I don't want to believe its the Machine ecm but it looks like that. Anybody know about the PBLO setting on the dash menu? What should it be?
"Parking Brake Lockout This feature is used in order to override the parking brake solenoid. This is done in order to keep the parking brake engaged. The machine will function as normal except that the parking brake is always engaged."
That's one I didn't know existed. Going to have a play when I get to the machine again next week. Every day's a school day on here.
There is also a setting for the blade on/off but I see no effect on the blade ie the blade works regardless of the setting. I think I confirmed that its an electrical issue as it drives if I power the pump solenoids. I'll post up any other symptoms/ problems and hopefully solutions if I find them. Thanks for the help so far guys.
The first thing that springs to mind in those circumstances is that someone has been getting "creative" with the machine wiring, or maybe the implement lockout solenoid valve (#10 in the illustration below) is stuck open......
Nige, the implement lockout valve is not stuck open. If the wiring is disconnected the blade stops working, if the wire is connected and the implement lockout switch is used the ecm shuts off the blade. The wire and return wire to the ecm are good with no shorts to power, gnd or even the 10v supply...if someone was creative. This is just another thing that points to a malfunctioning ecm.
So now I'm confused........... In your post #15 you say that there's a setting for the blade on/off (Implement Lockout I assume..?) that doesn't work. Then in post #17 you say it is working.........
Sorry if I didn't come across clearly. post #15 refers to a setting (that's on the dash through the menu just like the PDLO setting) this doesn't cause any change in the implement operation..it works regardless of this setting. Post #17 refers to the "lockout switch" which is a physical switch on the RHS console. Sorry for the mixup.
OK, clear now....... What exactly does the message say on the display..? I'm just wondering out loud if it might relate to the Auto/Manual switching of the blade control for use with Accugrade.
The screen has a pic of a blade, BLADE is written and on the top you can toggle ON or OFF using the buttons under the display, for the park brake PBLO is displayed with ON or OFF on the top. On other machines like the D6T there are options like blade raise ON/OFF but I don't see anything like that on the D4K. On the D4K We have the wiring for Accugrade on this machine but it is not installed.I don't know if its related.
BLADE with a pic of the blade and ON or OFF on the right side of the screen PDLO with ON or OFF for the park brake lockout Accugrade wiring is installed but no accugrade or its sensors or control are installed.
Late post, well after not working on the d4k for a while I decided to have a go at it again and it works!!! It drives and all functions work, I did nothing. I assumed it might have been air trapped in the hydraulics somewhere but it drove when I manually powered the pump solenoid sooooo I still don't know what the problem was. Maybe air in the pilot system, who knows. Maybe the electrical reset for itself??? I hope I don't get this again. Thanks for all who gave advice, information and had the patience to try to help. Cheers!
Got the same problem with my D3K LGP SN: 00D3KELLL000770. Anybody know what is it? Please help. Thank you
What problem exactly.? If you read through the thread so far it touches on at least half a dozen different things. Also do you have an Operation Manual.?
Good morning Sir Nige, the problem was parking brake lamp blinking when releasing the parking brake switch. The machine not driving, but the blade functions work normal. Anyhow, I manage to find the problem, the parking brake lock out is activated, so I just change the parameter to deactivate. I just don't know why it has been activated. I appreciate your response. I don't have any manual for this machine sir, maybe you can help me with this. Thanks,
I can help you in as much as direct you to a place where you can download a genuine Cat manual for $52. You can also buy the manual in a paper or CD format but they will have additional shipping costs on top of the price shown. Go to - https://catpublications.com/ When the popup appears click on "Continue as Guest". Put SEBU8213 in the box and click Search. The illustration below should appear. Paid with a credit card the download will be available in 5 minutes or less. FYI the O&M Manual also contains all the necessary information for carrying out basic machine maintenance as well as operation. It is NOT a service/repair manual.