Caterpillar 2008 D3G LGP BYR02093 was moving then intermittently would halt with "Park Brake" and "Hystat Bypass Valve" warning lights on dash cluster . Replaced "Park Brake" switch ( tested bad with meter ) . Replaced hydraulic filters . Still will not move at all now . Receiving code 245 for "Pilot Control Valve" . Blade will move fine . Machine starts and runs fine . Both batteries test good ( 12.7 volts ) while machine is off , 14.4 volts while running . One other issue is Engine Temperature gauge is pegged/maxed out ( with engine cool and/or off ) . Getting full voltage at engine temperature sending unit connector plug ( 14.4 volts while running ) . This voltage seems too high . Any help is greatly appreciated.
I sent you the schematic and the troubleshooting procedures for the 245 Code. We'll get to the coolant temp gauge later. Could be a bad temp sender unit. I would expect to see at least 13.8v output from the alternator on a good system, so 14.4v is not out of the question. I'd be interested to hear what others think. BTW kudos for posting all the information that you did (inc the Serial Number) in your OP. It makes finding information so much easier.
Yesir...I will work on dozer more today and post any news ... Thanks
Minor update .... After removing access plates .... today I plan to clean on machine more thoroughly before trouble shooting code 245 ....and before pulling any hydraulic parts . Want it super clean in case I change pilot valve .. I have ordered a new pilot control valve for hydraulic block and temperature sensor for engine coolant temperature ... Thanks for your help and patience ...
I think you're jumping the gun a bit on the pilot valve. You'll end up a bit red-faced if you find it's nothing more than a bad electrical connector - unless the parts are on sale or return........... These days the dealers carry so few parts in stock that everything has to come from a way away and for that reason they don't like returns for credit in any way, shape, or form.
Yesir ... I will utilize your trouble shooting info before pulling parts .. i agree not to throw parts at it .... Pilot valve and engine temp sensor cost me $200 and should be at dealer Tuesday or Wednesday. One additional note : gently tap on pilot valve and warning lights clear and dozer will move .... I really appreciate your advice and please continue to correct me if you think I'm going at it all wrong .... I appreciate your time sir ...
Now you never said that before. That kinda changes the prognostics. Just goes to show that there is no substitute for being there in person....... Forget what I said above and carry on.
Sorry for not posting that discovery sooner ... a friend and I discovered that Saturday night so I'm optimistic on that fix .... The wires entering ( I mean right at entry point ) the side of that valve are not in the best of shape either ..it's actual connector has been cleaned and looks good ...
I replaced the pilot control valve . This took care of the “hystat bypass valve “ dash cluster warning light and the 245 code . So now everything appears to work as it should but machine will not move at all now . No fault codes are being activated. As I toggle the park break switch I am certain I can hear the hydraulic tone change at pump . Only other issue is the engine temperature gauge pegged out but I have a new sending unit to install .
Does the blade still work?
Yessir .... blade has alway worked fine . Before changing pilot control valve , I could tap that valve to clear dash light and dozer would track . So I changed it out for a new one ..... now it will not track at all . Park brake light turns off\on as required.
Seems strange. Is there any way the valve could be installed wrong or plugged?
The Valve appeared to be symmetrical long,, and ported . It screws in and coil bolts down on top of protruding stem . I ask myself the same and thought of pulling it to check . Any advice is greatly appreciated .
I checked for codes . getting code 255 . Its for the "FWD , Neut , Rev position sensor" i think......