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Cat prv 350l calibration....
- Thread starter rmllarue91
- Start date
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!
So I threw a scanner on it - it showed coolant temp -37F, ambient was around 80F!
r20d12
Well-Known Member
- Joined
- Nov 29, 2009
- Messages
- 123
- Location
- oklahoma
- Occupation
- heavy equipment field tech since July 1990
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!
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.
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!
rmllarue91
Senior Member
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
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.
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Mobiltech
Senior Member
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.
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.
rmllarue91
Senior Member
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.
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.
rmllarue91
Senior Member
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
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
rmllarue91
Senior Member
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.