Hello, I have a new to me 2002 Cat 312CL SN CAB000745 5600hrs Problem: Machine does not swing cab or travel high speed. I really appreciate you sending the data to me. I have finally been able to get back to the machine to do some more troubleshooting. I believe I have narrowed the problem down to the implement pressure switch, and travel pressure switch, but I cant imagine they both fail at once. With machine on, I am getting 14.6v to the power wire on both switches to a common ground.(not in the harness) With the pressure switch(s) unplugged from the harness, I am not getting continuity through either switch with the machine running. Could I have low pressure there at those to switched? I am assuming it is pilot pressure? Should there be 24v to the K777 wire, or L971 wire or is the 14.6v at the pressure switch on the valve? FYI: Machine has brand new batteries. Every function works except for high speed and swing function. That I can tell. I am not getting to the coils for the swing brake or the high speed. Machine ran and operated fine at the end of December, was parked and sat for a month. Was restarted a month later and no swing. I see some rodent crap, but no chewed wires. Has not swung since.
I dont have the manual in front of me but should be able to crack it open tomorrow. I cant remember for sure the path on hydro flow. Ill grab book tomorrow and see if I cant find some info for you
Hey i never made it by to check the manual i should be there tomorrow though. I havent forgotten about ya
The way the wiring for those two switches work is that when the switch contacts close the ECM detects ground on whichever pin wire K777 or L971 connects to. The logic in the ECM can be basically described as "If I see ground - do A. If I do not see ground, do B." There will be a small "pull up" voltage on Pins 17 & 30 of the ECM. It will not be anywhere near battery voltage or even 12v, maybe a couple of volts (and milliamps in terms of current) at best. The 170-9335 pressure switch used on both those circuits is a normally open (NO) switch. The switch contacts are supposed to close at 384 ± 30 psi with rising pressure and open at 312 ± 30 psi with falling pressure.
I understand, any help is greatly appreciated!
Back in my tech school days, I thought I remember that cat signal is about 5-7vdc. That's why I was shocked to see 14.6vdc. Also, I should be able to jumper those switches for testing since they are only 2 wire? I will take some transducers out and put them in the switch spot. I work for a hydraulic company that manufactures monitoring equipment so that won't be a problem. Thanks for the specs, I don't have a service manual, just a schematic. Thanks for your assistance.
I was able to get to the machine today and figured how to pull codes. Active Codes: 69:1162-04 Logged Codes 69:1162-04 69:1161-03 69:1161-04 69:587-03 69:587-04 69:374-05 69:376-05 69:581-05 69:167-08 69:588-09 Logged Events: 69:100 69:17 69:600 69:179 69:43 I started on the "swing is inoperable" on the troubleshooting but the next step says to disconnect conn105 but my schematic doesn't list connections that high. I also made a quick video clip of the noise it makes when you try to stroke the joystick controls side to side. The machine does come off idle when you hit the controls like it should. I have a larger video of running through all the functions, but its too big to attach. Would have to use Whatsapp or something similar. Again, thanks for your help. short video of sound video running through the functions
Where does that procedure come from.? Can you upload a copy. I’ll look up the 1162-04 Code and get back to you.
I found the procedure. Note this at the top of Page 1. It is all regarding the swing brake not releasing and three specific Active Diagnostic Codes, none of which you have. And only one of the three, 374-05, is even in the list of Logged Codes. More info on the 1162 - "Automatic Travel Speed Change is Abnormal". Seeing as that is Active I suggest that you do the troubleshooting for that one first. The procedure is listed in the same manual.
Can you send it? I don't have the manual, it was sent to me.
See attached. I haven't read through much apart from briefly skimming the first page.
Well, fortunately I have found my problem area. I have good continuity from the elec panel 12pin Deutsch connector to the brake sol and the computer to the 2spd sol. I am not getting continuity from the 12pin connector to this K906-GN-18 wire. I pulled the belly pan off under the operators station and it is PACKED with packrat house. WHAT A MESS! Since there is only a few inches to access the area where I need to, does the seat come up and heater box come out so I can access this area? HELP. I have put 8 bags of poison in it and they are gone. One was in this area. Since I did not know which connector it was, I pulled a part 4 of them. of course there was a little corrosion and a couple broke off pins. I think I found the right pin and socket on amazon and crimper so I guess I will have to rebuild the bad ones. Any pointers? WHAT A PITA!
Them little SOB cause so much trouble. It seems I spend more and more time trying to keep the suckers out, every year. Around here it’s open season on chipmunks with a rifle, nevermind squirrels. I have taught my dog to seek out field mice and kill them. I want another cat but wife says no. Right now, she makes up TP tubes with cotton balls soaked with peppermint oil, seems to work better than mothballs.