Cat 966G series 2 serial number CAT0966GJANZ01226 I have a 966g ii that has been giving me alot of trouble with an oil pressure warning light and an audible warning put a mechanical gauge on it to verify oil pressure and checked out. so for the hell of it threw an oil pressure sensor on it and to no prevail my issue continues. this issue is very intermittent it seems to come and go and when it comes you do not want to be in that loader. Did some digging and pulled a 274.03 code off the service information in the loader i believe the code is an out of range high for atmospheric pressure i plan to replace it, after doing some digging i read that all the pressure sensors use the same signal wire and ground with their own returns to ecm so i was wondering if this sensor could be apart of my oil pressure warning light fiasco. was looking to see if i am headed in the right direction. if not i beleive i may be looking at an ECM any help would be greatly appreciated. Thanks
When you first turn on the key and the Monitor panel completes its self-test does the SERV CODE icon go off or stay on.? How are you accessing the Diagnostic Codes.? Don’t bother with the 247.03 for now until you have diagnosed it properly - if it is even active. Do you have an electrical schematic.? Because you are probably going to need one.
I think I would run a gauge up to the seat so you can monitor the pressure. You state this is an intermittent problem........those are tough. You've already replaced the sensor, so we can call that good for now. Could be an electrical problem, oil pressure relief problem, etc. If it were me, I'd run a line and gauge up into the cab. When you get the warning, you can always reference the gauge to see what's going on.......hard data. I am a big fan of gauges......hate idiot lights. Did you pull the pressure off the SOS port at the oil filter?? Just curious....... I have tapped that on a CAT 320 and permanently mounted a gauge outside the window. The coupling/ quick connect is CAT 243-3133 The 243-3133 Quick Connect Coupler (Fluid Sampling) provides a quick connect coupler that attaches a portable particle analyzer to the sampling valves for easy use. The quick connect coupler works with the 8C-34467-X33878C-3345 Fluid Sampling Valve As. The quick connect coupler has a black oxide finish for excellent durability. NOTICE The 243-3133 Quick Connect Coupler (Fluid Sampling) must not be used with the 183-7264 Fluid Sampling Valve As or the 183-8652 Fitting As. Use of the quick connect coupler with the dual purpose valves can damage the valves and result in component leakage. Table 1 Technical Specifications Operating pressure 3500 kPa (500 psi) Burst pressure 1400 kPa (200 psi) Maximum operating temperature 34 to 107 °C (93 to 225 °F) Seal material buna N Connector 1/4-18 NPTF 1/4-18 Femal NPT connection on back
as far as the monitor self test when first turning the key on the lights do complete their self check and the park brake light stays on just because its on. the serv code does stay on. i only accsess the service code through the machine i don't have accsess to sis or et. as far as electrical schematics i do not have as well. unfortunately this is the best service information i have and it is for an H series machine https://constructionloader.tpub.com/TM-5-3805-291-23-1/TM-5-3805-291-23-100398.html i know its not the greatest but its all ive got to work with at the moment so ive been using it loosely
I had run a gauge up into the cab about a month ago when problem first began, everything operated as normal, i pulled out the releifs and inspected them as far as i could tell they where in good shape. the problem had dissapeared after playing around with the harness so for the hell of it i repinned the connector, problem dissapeared but is back for revenge and has got me really kicking my ass
This is the very rough schematic i have been using and just back probing and using my multimeter it seems to be accurate
First - don't panic........ 2. The fact the SERV CODE icon stays on after the self-test is indicative of one or more Active Diagnostic Codes. 3. Electrical schematic on the way. Check your messages. Back to #2. You need to read the Click box thread. Here is a LINK to it. Take special notice of Posts #50-52 on Page 3 which give you instructions how to McGyver something to get the Monitor into Service Mode and read the Codes if you don't have a Click Box. Remember that while in Service Mode and as the Code list scrolls across the monitor ONLY the Codes where the SERV CODE icon is lit up are actually Active at this time. Make a list of ALL the codes you find and mark the ones that are Active.
Take a couple of photos of the Codes as they are on the screen. There are two possible ways they will display which will indicate the type of Monitor Panel you have installed. It might be important later.
Intermittent electrical is so much fun, isn't it?? Assuming you still have the gauge up in the cab......when you get the warning light, gauge is still reading correctly (normal oil pressure)?? Or did you take the gauge out??
How is your knowledge of electrical schematics and electrical theory?? Just wondering if you understand how your pressure sensor works. Not asking to be derogatory......just trying to get a basis of your understanding of it.
it's fairly well, no expert but i understand 5 volt reference and out of range hi and lo, some can bus stuff, the cat 7 volt open circuit reference. i'm still new to some diagnosis but this is part of the ride i suppose haha. as far as the gauge i haven't got in the cab any more but after ruling out this harness i may take a look at it again
Nice.........there's always a first time for everybody. And it's only easy if you know how to do it. Leave the gauge in the cab so you can reference it when you get a warning. Who knows, maybe the oil system is actually doing something funky and weird and the electrical is fine. Could be the relief valve is hanging up every once in a while........but you said it's come back with a vengance........so, who knows.
What is this 7v reference of which you speak.? Please enlighten me. The engine pressure sensors are PWM type and are supplied with 5v fronm the Engine ECM. Do you have a DMM that reads duty cycle.? You might need one.
I see the 966G2 has the 3176 I have seen a similar fault on a 3196 in a 730 where the atmospheric pressure sensor -3 code was causing low oil pressure warning while the fault was active. I believe the atmospheric pressure sensor is taken into account with all the pressure sensors on the machine.