Hi guys, I have a Hitachi EX200-3 14C-8278XX probably 15000hrs. I was working with it, it works very well as I do my work at perhaps 1250RPM, that's fast enough for an old guy learning and I really like how the machine works. Then just like that as I finished traveling and was about to put my thumb full of trees on a pile the engine dies. Restart the engine. The engine is on full load, smoking black pulling all it can with no activation although under this fully loaded engine I can work the thumb, any other function stick, boom, bucket or travel it dies. The PVC light does not flash, I don't get the 5 volts at various places where they say it should have rather i get 1.6volts approximately. The N sensor tests OK, the A sensor unplugged, still no computer flashing light, changed the DP sensor with no effect, the two solenoids on the outside far right of the pump test 15 Ohms.... could it be the PVC fried although I opened it and found no oder or burned looking resistors? Could the wiring harness be stressing the system with to much resistance therefore frying the PVC? Can I connect a new PVC and turn on the key just to see if the light flashes without damaging it? I noticed the lowest amperage fuse in the fuse box is 3 amp, they call for 1 amp I believe. Any help would be appreciated. Also if someone has a Dr ZX for sale I'd be interested.
All the 24 volt power and grounds good at the PVC ? Check your messages.
There are two black wire wires grounded to the structure base where the controllers are fastened to on the cab floor 17mm socket size.
I will look at that again tomorrow.
All grounds and lives are good, seeing its remembrance day my neighbour who's a computer tech/shop owner came to visit me there so he checked the resistor and capacitor in the PVC and he said they checked good.
The bottom controller, correct? If that light is not flashing, then there is an issue with the 5 volt reference circuit, or a controller issue. If that is the 5 volt reference circuit, then there is a short somewhere. And if there is a short, then the controller shuts down and the light stops blinking. The short could be a sensor, or the wiring. Start with unplugging all the sensors. Does the 5 volts come back? If so, plug the sensors back in one at a time until the voltage drops. If the voltage remains low with every sensor unplugged, then that one is a little more difficult to troubleshoot. There could be a wiring issue and that could be tough to find. For what it is worth, those machines have a poor history with wiring. I wouldn't until you are sure you don't have a wiring/sensor issue. F7 should have a 1 amp fuse. Never, ever, put anything higher in the spot.
I installed the new PVC with a 1 amp fuse and everything works hydraulically but now I worked the machine for 3 hrs about and I noticed the Glowplug light comes on and then went off. few minutes later I shut off the machine, no glow plug light on that time but tried to start it and while I start the glow plug light comes on and you can hear its not cranking like it has, laboured. Batteries check 24.3 volts, engine not running the glow plug cycles when turning the key to the opposite side of starting. Any ideas on that issue?
Per the schematic screenshot ,the glow plugs are supposed to be on when cranking.
Should the glow plugs be cycling while operating the machine?
No , the glow plug relay fuse # 20 is supposed to be powered only when the key switch is held in the “heat“ position or the start position. Check if fuse # 20 is being powered continuously. Per the manual,the monitor controller should never allow more than approx 20 seconds of glow plug operation. It‘s possible the monitor controller is doing its job and creating the cycle.
Is the monitor controller sitting on top of the PVC? Can I pull the fuse #20 while the engine runs so it simply doesn't energize the glow plugs without creating more issues?
The EC (engine controller) sits on top of the PVC. The monitor controller is sitting on the same shelf ,just to the right of the PVC. . If fuse 20 is continuously powered , would point to a defective key switch. Yes you can pull the Fuse #20 while the engine runs to disable the glow plugs.
A few days ago I installed new batteries, now the glow plugs cycle when I turn on the master key, with the cab key off but don't cycle randomly when in operation. Also now the glow pugs don't cycle when the the key is turned to glow plug position but on while starting, I checked the external wiring harness number and it comes up as a harness for an EX300....???
What indication do you have that the glow plugs are cycling on with the key off ?
I turn the master key on and by the time i get into the cab it's another 5 or 10 seconds and it goes off. With not touching anything.
What goes off ?
I assume it is the glow plug indicator light that goes off ? Did you remove fuse # 20 ?
Now I pulled the fuse#20 and turned the master switch on and no glow plug light, then, put the fuse back in and turned master key on, no glow pug light till i turned the engine start key on(opposite to start) to activate the glow plugs. then the glow plug light cycled as it should. Was pulling the fuse a reset?
Is the master disconnect switch something that you installed recently ?
Nope that's been there for as long as I've had it. 2 years.....
A reset is a possibility. I suspect the controllers / circuit boards don’t like being powered down completely by turning off the battery master disconnect.
My mistake on the description of the master switch. The typical battery relay has been replaced with a manual key type turn on and off relay, so the controllers still get the power when turned "off".
More questions, i recently resealed the main control valve and installed a new wiring harness inside and out on above mentioned EX200-3 Hitachi excavator. I turned the key to the run position, all looked normal, EC and PVC lights flashed normal, then started the engine and all lights on the dash red and green come on and the buzzer buzzes. Engine doesn't load up though and now the PVC light doesn't come on, EC shows 4 and 5 flashes?? Hate to ask but anyone have idea's, the book doesn't articulate what the 4 and 5 flash means
From what I understand the flashing light on the EC is not used to determine any fault codes/issues. You will have to figure out why the PVC lamp is not flashing approx once per second as it should. All the fuses are good and not exceeding the proper amperage especially the PVC 1amp fuses #4 and #7 ? Do the red and green indicator lights on the dash eventually go out and does the warning buzzer eventually stop ?
Fuses are good, the red and green lights and buzzer keep going till I turn off the machine. I ran it for about 5 mins. This all worked when I pulled the old harnesses out.
The monitor controller behind the operator seat is mounted solidly ? Double check the 2 plugs at the monitor controller are fully seated , the pins in the monitor controller are all straight and also check if one of the wire harness terminals got pushed back and out of position.
The PVC, EC and monitor are tight, I checked the connections to the controllers, all looks good. I checked the live wires in the PVC plug, they have 25 volts. Tried to unplug the interior/exterior wiring harness plug but couldn't get it undone, try again tomorrow. Also checked the pump harness to main exterior plug, all looks good. Checked random plugs, they looked fine, I checked the fuses, I hadn't gone over what the factory had installed. There was way to big fuses in the fuse panel in the wrong places so I pulled all fuses and installed the correct fuses in the correct places#$@^%&.
You said all the PVC powers are good , how about all the PVC grounds are all good ? If the grounds are good I would open the PVC looking for a burnt component.
Yes forgot to mention they where testing good also.
Yes, they where good as well, A bit of info and question here. According to the parts book I installed the new 0001835 interior cab harness, 0001836 exterior harness, now can someone tell me what the part number is for the pump harness? nothing shows in the parts book.
An OEM main wire harness # 0001836 was one piece and included the wiring and connectors for the hydraulic pump area. Not sure how the aftermarket harness’s are configured.
Originally I ordered the harnesses according to the EX200-3 parts book which says I need the 0001835 interior and 0001836 exterior harnesses. They tell me its the wrong harnesses. So the 0001836 harness doesn't come complete with the pump harness so I need something for the pump. Communication with manufacturing overseas is dicy to say the least. "They" tell me I need the 0001835/0001858 interior harness with the 0001836/0001066/0001045/4296868 exterior harnesses and a 3094204 pump harness..........I had originally ordered the 3094204 harness with the 0001835, 0001836 harnesses and it fit and looked good but all the yellow, red and green dash lights came on when engine running. I'm confused.
In terms of the monitor operation , I believe the # 3094204 pump harness only connects to the engine oil pressure switch and the engine oil level switch. You could try unplugging those (2) items see if it has any effect.
I'll have to get that for the second time...... It'll take a while. At least I'm gaining some experience. And I'll try your suggestions.
The harness they sent 3094204 connects to the rear end of the engine the two plugs in the picture, the RPM sensor and the rest of the pump plugs. Are they not accurate with their harness or the description?
Today I installed the new 3094204 harness, the oil level sensor was not pugged in on the old harness so I didn't connect on the new harness. I turn on the manual battery relay and with the old harness the battery and oil pressure dash lights would come on, only the oil pressure light comes on. I start the engine all dash lights and warning buzzer come on. Engine running, alternator charges 28.19 volts and charges 20 amps. before engine start, batteries sit at 25.2 volts. Ran engine with oil pressure wires disconnected, still all dash lights and buzzer are on.
Looking like the monitor board is bad. I think if it was a harness issue triggering the engine oil pressure indicator the emergency relay would be triggered as well and the engine stop motor would shut off the engine.
What Ive forgot to mention the engine stop motor was disconnected from the old original harness so I didn't connect it with the new either, also the dash lights all come on when engine is running and when the engine is turned off it takes a few seconds for the oil pressure light to go off. This was the case with the old original harness as well.
Are you referring to the Monitor controller behind the seat beside the stacked PVC and ECU or the armrest dash/cluster/guage monitor with all the lights coming on with the engine running? Would you have a part number for the monitor?
Sorry, I was referring to the monitor controller behind the seat. Everything in the monitor except the fuel gauge,temperature gauge and the monitor back light are controlled by the monitor controller. Not sure where the buzzer is actually located but it is also controlled by the monitor controller. See monitor/ monitor controller schematic below.
Monitor controller part # 4325825 subs to # 4688258 . The “monitor panel” is basically made up of a panel with mounted gauges, and a wire harness with (14) indicator lamp sockets. See screenshot below.
Anything I need to pay attention to before I install the new Monitor controller like disconnecting the batteries and so on?
Disconnect the batteries would be good.
I installed the new monitor controller and still have the same results. All dash lights come on except the alternator light and buzzer going with engine running.
New aftermarket cab harness, new aftermarket exterior harness ,new aftermarket “ pump harness “, and new monitor controller, same result. I don’t get it ! I know earlier you had unplugged the oil pressure switch to try and cancel the buzzer. Try unplugging the coolant temperature overheat switch
One last thing I can think of , per the manual “ When the key switch is turned to the PRE-HEAT, "ON" or START position, it is normal for all monitor indicators to come on.” Double check the key switch isn’t stuck in preheat. You could prove if it is creating the issue by removing the glow relay fuse # 20 disabling the glow plug circuit.
I disconnected the overheat indicator and still the buzzer and all lights come on. I connected a test light right off the glow plug circuit on the engine, the glow plug power goes on and off as it should.
Another question, the all dash lights on and buzzer going situation, is that just engine related or could that be a problem with another part of the machine?
All engine related. See screenshot below of monitor and monitor controller portion of the electrical schematic. The emergency relay is triggered if the engine oil pressure switch closes (due to low oil pressure) the oil pressure switch providing a ground. You said earlier the engine stop motor wire harness is not connected so not really sure if the emergency relay is functioning properly or not. I’m questioning if a defective emergency relay could be providing a ground. Un plug the emergency relay , see if has any affect on the buzzer and lights.
Emergency relay location screenshot.
I unplugged the emergency relay and still the same result.
Refresh my memory, was this buzzer and monitor indicator lights issue ongoing before all the wire harnesses were replaced ?
Nope, no issues like this at all. I replaced the harness because I noticed some wires where bare and looked like they'd been there for a while and oily.
The issue remains when the new “pump harness” is not connected ?
Yes, and the engine would turn over but not fire up with the pump harness unplugged. Then I plugged in the harness again and engine starts and runs as it should. The battery/alternator light in any case does not come on after the new harness has been installed.
I unplugged the two wire plug on the alternator, I started the machine and no alarm and dash lights off. Sooo i compared old harness to new, the wire colours where opposite so I switched wires, plugged in, started engine and all cool except the hydraulics are still very slow but build pressure when cylinders bottom out.
Have you checked if the angle sensor is adjusted to spec ?
I unplugged the A sensors a fellow contributor said to do in another thread on HEF, started the engine for it to load up but it did not.
I assume you meant to say “unplugged the (2) pump solenoids “
I meant to say the angle sensor. How long should the engine run normally to load up?
See screenshot below for the procedure to check if the angle sensor is adjusted correctly. Start at step 6. The voltage measurement tool isn’t critical, just backprobe terminals #2 and #3. Terminal locations are shown in the second screenshot. .
I did the sensor test, I started the engine, unplugged the solenoids, ran for 5 mins did not load up. Stopped engine, unplugged and replugged the solenoids started engine, it started smoking black I let it run and unplugged the solenoids, run for 3 or 4 mins, stopped engine, took a reading off of wire 2 and grounded to the pump body, had 3.8 volts, adjusted to 4.4 volts, reconnected solenoids, started engine and now its loaded up and doesn't unload. Both computers are flashing or were during the course of this venture. Ive compared the old harness 1836 to the drawing and I'm finding the alternator wires do not all match with what the drawing shows. The battery/alternator dash lamp does not light after the harness swap as it used to, although the buzzer now only activates when i turn on the glow plugs and it used to not do that. I'm leery of the harness seeing the old 1836 doesn't match with the drawing, has it been altered to make it work?? Did I make a mistake in resealing the valve body? I was following the book diligently.
What are the wire colours in the “pump harness” going to the top and bottom hydraulic pump solenoids ?
The top solenoid is a Black and red wire and blue and red wire, the bottom is Black and red wire and a yellow wire.
I believe the wire colours per solenoid position are correct. With the engine running and hydraulic controls in neutral the DP sensor output voltage at terminal #2 should be 4.5 volts. The DP and angle sensor connecters are the same. Do you know how to check for service codes ?
Sorry I don't know how to check for service codes.
Also, does it matter if the pump is loaded for the DP Sensor test?
No
You can check for codes using the red LED on the PVC behind the seat. See the link to an older thread below. Post #14 shows how to enable the self diagnostic which sets a light blinking sequence, (if there are any codes). HeavyEquipmentForums . . The PVC is the bottom controller and EC is the top controller. Ignore the light on the EC. if there are any codes ,the light on the PVC will blink in a pattern of long and or short sequence.
The code I'm getting is a flash every second. The DP Sensor voltage is 4.74.
If you jumped the 2 appropriate terminals in the DrEx plug (per the older thread mentioned in post #69) , I take that as NO service codes found.
How many volts to activate the pump solenoid valves? when i activate the auxiliary valve (thumb) the engine runs less powered down and the same pulling the stick in, all movements have loosened up a bit. I checked the resistance on the solenoid valves, today 16.2 ohms. Wondering if one of them isn't getting the power to function?
The pump control relay is closed by the PVC when the key switch is on sending 24 volts to the pump solenoids . With some aftermarket PVC the engine must be running before the pump control relay is closed. The PVC controls the ground of the individual pump solenoids turning the solenoids on and off quickly as needed and controlling pump displacement. See pump control relay location in screenshot below.
On your EX200-3, to identity the proper location of the two identical pump solenoid wire harness connectors (ignoring the wire colours of the “pump harness “). Check for continuity between terminal # 2 of a pump solenoid connector and terminal #103 of the PVC connector. That combination would plug into the lower pump solenoid. . .
Howdy, I think I got the problem fixed. The new harness had two wires on the solenoids labeled wrong behind the cab. Then found the PVC was fried perhaps from the alternator wires assembled (exchanged the two wires)wrong as well. Installed a new PVC, seems to operate as it should. Thankyou very much for your help.
Glad you got it figured out. It would be a major PIA to diagnose if wires were labeled wrong.