3ml365 machine had lots of electrical and hydraulic issues got most straighten out but it's acting like it won't save calibration. Machine is super slow in auto. If you switch to manual slow mode it's a little faster than auto. If your in calibration sub mode machine will respond to changing the two vaules but if you shut machine off or hold service key it goes back to super slow. I didn't have book with me and couldn't remember how to see if there's codes. I ordered a new prv valve. I will install check codes and try to recalibrate but was looking for some experience with this. Also if someone has experience with adjusting pumps i could use some pointers. I currently don't have a differential pressure gauge or large enough flow meter so I'm not sure how much I can do on this with just pressure gauges. Thanks hef
Have you checked your powershift pressure with a gauge? Does the engine bog way down when you operate functions? Engine will die if you bottom out a cylinder? I've never had to adjust pumps on one. Its always been a control issue or a failed pump.
Have you checked the engine throttle calibration first? The video below shows how to get into the A series monitor panels for diagnostics.
I did check power **** pressure but don't remember once I get the calibration issue I'll re set power shift pressure. The main issue I'm having is the prv valve won't hold calibration. On monitor panel when I exit calibration mode the prv totally destrokes pumps When in calibration the two values for prv can be changed and you get set to where machine operates pretty good. I did set the engine rpm to spec the speed sensor was bad in bell housing also
Ok. I understand now. Im wondering if you have an issue with your CAN and CAT data link harness. I've not worked on a 350L but I saw no one else responded so Im just trying to help. Some machines will use one data link for calibrations and one for the normal machine function. Im wondering if the data link for calibration is working but the other one in not. Could be a broken wire or a failed terminating resister. There should be something in the fault codes leading you there. The "L" series is hard because the electronics were in their infancy and don't give you enough info some times. I hope this helps.
Checking fault codes is probably the logical place to start. Here is the menu part of the diagnostics. I don't have anything any deeper just yet. Caterpillar Electronic System Computer Controller Lights Yellow Monitor signal out, data problems Red Controller bad Green All OK. Data Mode Push alarm cancel button and power mode until throttle indicator number shifts. Use power mode to cycle through the Data modes. The indicator lights on the left side of the panel will flash indicating the current mode. Power shift Engine Speed Engine coolant temperature Hydraulic oil temperature Analog/Digital conversion Real time Error codes (Each code will be displayed in order) Digital output (Use work button to set each of 21 points) Output Control Display Code To stop Data Mode Push alarm cancel till dial setting changes Error Codes Push service button and power mode button until Mode 1 indicator comes on. Use AEC or washer button to cycle codes. To Clear Push AEC, Power Mode and Travel speed for about 3 seconds.
Okay I'm at machine now if I check prv in data more it shows p17 as soon as a function is pulled witch equals no power shift pressure I'm plugging a gauge in now to teat accuracy. If you go into service mode you can change calibrations and it will work untill you log out of service mode. Also going to try the prv sweep test in few minutes
Passes a sweep test voltage changes with calibrations and so does pressure out of calibration mode it's 30 psi power shift pressure. In calibration mode will go all the way up to 430 psi power shift that's way too fast lol this is with brand new prv coil and valve seems like it's controller.... No codes came back after I deleted history and no active codes while running. Any thoughts well come
I think i said it earlier but sometimes, jumping between threads i get mixed up. Some machines will talk through one data link during calbrations and another data link during normal operation. If the "normal operation" data link is defective that could explain your problem. Ive had an ECM fail but thats an expensive part to just change if your not positive its bad. If you have the schematic you should be able to see if it has two data links. On a newer machine, a code is given for any data link issue but anything before the C model is sometimes impossible to get the info you need. I hope this helps you. Let us know
All technician can do with CAN BUS is check wiring, powers and grounds, test resistance of terminators and that’s pretty much it. Calling an ECM bad - is a hard decision because it is expensive! There’s one more thing you can do: if you have someone with two channel scope ( like friends who work at automotive dealer or shop who have the scope ) - connect to your network and look at the square waves - they should look square, clear straight lines and mirror each other, if not - try to unplug various ECMs and see which one distorts the signal. But checking for solid powers and grounds is a MUST. Very often ground gets loose or corroded at grounding lug on the body! Sorry for intrusion!!!
One more thing: the “fast” network must have its terminators on the network harness, two of them usually 120 ohm each but connected parallel so you should have 60-70 ohm when you check. They look like empty wiring connector socket with epoxied end where usually wires coming in. The “slow” network usually having its terminators inside ECMs.
Good sound advice TVA! I had a snapon Vantage meter when they first came out. It was great for checking sin waves. It was 4000.00 back then. No telling how much now. It of course eventually quit working and all they wanted to do was trade it for a much more expensive one. Lol.
There’s actually a tool sold by Pico Automotive, it is NOT a scan tool but a scope interface for your computer, all it can do is put your voltages on the screen in a graph form, it is very good tool if you know what you doing. It is not cheap but not as expensive as full blown brand scan tool. There also a lot more cheaper handheld two channel scopes, but those are limited in choice of resolutions and time frames and the big deal for me is I’m getting older and can’t see good anymore - so I need a big screen.
I never worked with CE brand scantools, do any of them have scope build in?
That Vantage was a graphing meter but it was crazy fast and could catch even tiny glitches in the signal. I had an old Volvo A25C with a stupid transmission. I finally tapped into the engine speed sensor in the flywheel housing. The signal looked like a small child got ahold of a ball pint pen! Just funky scribble mars. When i removed the sensor the end was broke and it was just a ball of copper wire. Lol. New sensor fixed stupid transmission
The Vantage was actually a scope and a volt meter. Was a fantastic tool!
And probably like it happens often - no codes?
One more, subtle one, Engine speed sensor give of believable but wrong signal, gonna have to use handheld rpm counter and compare it to what ECM reads.
Yes. But not only speed sensor. A very common one is Cat D6 will get a crank but no start condition. No codes. But the machine will have been sitting there long enough to be cold and water temp will show in operating range! The ambiant temp is too cold for the engine to start without switching to its cold weather map so it wont change the timing and wont start. The first one i ran into kicked my butt! Didnt notice temp gauge till second day. Put a variable resister inline Turn it till temp read cold and engine started great!
No codes!!!!!
Reminds me one time my friend came to me with his Nissan Maldonado a little scared, and told me: do something with this car! It drives like it is a hot rod, and burns fuel like one! So I threw a scanner on it - it showed coolant temp -37F, ambient was around 80F!
Thats awesome. One of my friends found he could unplug his Cat powered service truck water temp sensor for the ecm and it would never come out of cold mode then he put vise grips on his waste gate hose. Lol That one is a mess now. One all us old Cat guys love to torment but respect very much!
If that turbo would have been the newer- small one, it would be in pieces in no time, but the old big and slow ones - they don’t care, just whistling along!
OP is not checking in! Must be busy. This thread reminds me, got to buy my self some kind of a cheap scope, since I moved from Seattle I don’t have access to my friends cool toys anymore!
Do you know how TEXA doing with CAT? I herd when it comes to CAT and JD it doesn’t do everything.
One guy with DD60 didn’t realized that his hose was rubbed through ( I think the one that feeds compressor air ) on the opposite side of an engine, so basically he lost a boost pressure, but he also lost wastegate control because there was no pressure, that small fast turbo came apart on him. He was on his way back from Forks WA, right smack in the middle of Olympic National Park. No boost, no turbo, truck barely crawled, no cellphone service!Tow truck showed up only next morning, he said pack of wolves visited him at night.
Lol wow about the wolves! never heard of texa until you brought it up. Not sure how it works. Cat is stingie. That stuff frombdiesel laptops is bootlegged but works great
When it comes to proprietary stuff, IMO the one worst than CAT is a Hyster, they even built ass backwards pump drive with the chain and taper roller bearings and cooking pot style sump pump for their forklifts - just to try and make a buck on parts sales. At least CAT have the best of parts program and dealer network in the nation! Those suckers ( Hyster ) manufacture something for few years, then discontinue and even stop making parts for it! When supply runs out - they want you to buy new machine. They had a gear pump that had non standart combination of shaft to mount and with integrated into rear cap priority valve, when that pump died we couldn’t find replacement, but I found a way: went to Chelsey PTO dealer ( the one that sells stuff for dump and tow trucks ) they had Parker P-16 pump, that pump like a lego LEGO, they had all kinds of front and rear caps with all kinds of mounts and port configurations on the shelf. So I matched displacement as close as I could slapped right caps on it and it cost me $475. Put cheap Brand adjustable priority valve on the frame, and replumbed that thing. It was 8 years ago - that thing still runs like a champ today!
I missed the part about the two sets of communication wires I will check schematic. I'm assuming they would be between display and controller? Side note am I missing where the lights on display can change colors I've only seen the red.... Found a good used ecm for $800 reman is $2000 but need to finish diag. First thanks for the help I love being able to converse with fellow mechanics
I’m not sure about this particular machine but and what r20d2 meant by that, but very often there’s two CAN BUS networks, fast and slow. Fast is what it called- fast, have really high update rate, but very prone to loosing communication because of interference and distortion of the signal. That one MUST have two termination resistors on each end of the network to combat distortion, if something wrong with those network can start doing all kinds of crazy stuff. Slow is acts as a backup because it is not highly vulnerable but slower. So when everything is doing good the fast network is running things, if something start going bad, slow kicks in. I’m not a CAT guy but (and don’t know for sure) running slow network to diagnose controllers would be my natural choice as it is more reliable network.
I am wondering if you are actually saving the calibration before you exit. If you exit before holding the save buttons it will not hold the calibration. Also when you are calibrating you are only setting the high and the low end of prv pressure once you leave calibration the ecm controls the prv according to engine rpm. If you have a false rpm signal you need to fix that first.
About false rpm signal, like I said earlier this one can sneak up on you!
I'm using the alarm cancel button to save I'll double check procedure. When I go back to check or recalibrate it shows what ever I left it at. Rpm seems right on display idles somewhere around 1000 and wide open is 2200 as I remember. Did verify awhile ago when I installed new rpm sensor with multi tach. Machine reaches high. Rpm The issue I have is prv voltage drops below 2 volts power shift pressure is 30 psi and if I watch prv on display it show p0 as soon as I move a function. And will only show p17 when I'm not moving a function. It appears to save prv high and low in calibration but data mode it's either p17 no movement and p0 with any pilot pressure.
So after stating above. Controller is probably missing an input or getting a bad one and cutting prv to minimum. I know prv is getting some power when it I run. And it can change when I force and input in calibration mode. So maybe prv system is working fine..... I just have a bad input.... Banghead
You need a scope and i need to toOne is a "cat" data link one is a "can" data link and yes between the controller and monitor. This a great site. Good nice folks
350 Don't have can bus
Sooo it was all related to the ground for prv solenoid. The wiring all goes though the pump switch for auto and manual. Someone had ground wires reversed and one had a bad connection. I checked ground at prv somewhere In process it read under 10 ohms but it had a weak connection. Weird part was the display for prv value was dropping to zero like it was seeing low rpm. As soon as I swapped the two grounds on switch and fixed the bad connection the little red lights on monitor went out and prv started working right. Wish I had more time to dig into why and how it worked but had another machine to tend to. Thanks for the help was getting ready to throw parts at it.... Glad I asked on here. I've had some really tricky ground issues lately had one I posted on here about on a 3056e. Took three years dam thing ohmed out fine but when cranking shot over 100 ohms I thought it was a voltage issue because boosting power helped. Thanks again love the ideas and even the ones that seem off base I'll be doing something else and be like that's what they meant.
I always suggest checking grounds by loading the wire with something like 55watt headlight bulb, if there’s bad connection, or wires rotted inside and invisible - you will see it when light will be dim. Just ohming out will not show those issues, multimeters at most puts out 500 milliamperes. Just need to be careful with female connector in sockets - don’t spread it and make good and tight connection in socket, then touch the other lead to B+, this way will be less prone to arch damage the socket connector.
That is great that its fixed! The hardest ones are those that someone else "fixed" before you got there.
Hi sir may I know how to accessing into service mode?
Welcome to the HEF. May i know your machine's model ? make sure to post machine's model & serial number as well when you post.
Assuming as that your machine is a cat 350l i have sent some information to you. check your inbox.
Excuse me. Can i have it too. I want the information about how to accessing into Calibration mode and Data Mode on CAT 350L.
Hi Thomas! Welcome to the HEF. check your inbox.
Thanks sir, I have send you my email.