ACS disable S185 Turbo / ACS problem

[Michael_S185]

Hello guys, I have an old Bobcat S185 turbo with an S/N 51… I think 2001. The machine is very good and I use it from time to time to do some work with. I write you from Germany, so sorry for my bad English! The people here don't use bobcats, but I love the machine and repair it always by myself and don't want to change it! I have a problem and will be very happy if you can help me or give me an idea what to do! I don't know why but I got an ACS error 34-02 that should say not connection do the ACS. I opened the wiring schematic and checked as follow: -all power supply wires are ok and I get 12V on them J1 and J3 -all ground wires to the ACS are also ok -the 3x CAN-wires that connect to the Bobcat controller are not broken and I can measure truth them -when I disconnect the actuators, the pedals and handle sensors nothing changes and the error is still there So I think the ACS unit is broken, but I can't get a new one here at the moment very fast… also it is very expensive! So my question is, can I use the standard food control and somehow disable the ACS? How are the actuators controlled from the pedals? In the wiring diagram there is just the ACS unit missing, but I somehow can't understand how the pedals control the hydraulic pump without the ACS… Thank you!!!

 

[Michael_S185]

Hello again, So I got the parts manual and was able to see how the linkage works on a non-ACS-machine … it is a non-electric control system that is very much different than the ACS system. No actuators and no pedal/hand electric to control with. This will not be very fast to do and I am not sure if the valves can be controlled "manual" with the actuators connected. I will go to the machine later and check. I now try to understand the schematic and to find a way to use the actuators without the ACS control. There are 5 wires that are connected to it: -4790 – forward connected to the ACS -4780 – backword connected to the ACS -2770 – ground -1630 – 5v support voltage that is also connected to the other actuator, the hand hall sensors and the pedals -4770 – a signal that is in the middle of 2770 and 1630… this is the signal from the position sensor or something. So I wrote this part this morning before I worked on the machine! Now the upgrade: I checked all electric options I had in mind. -Added 5V to the support line – no change -checked the max voltage (15,4V) and disabled the generator to be sure there is no overvoltage error -checked again the unshielded and shielded 12v lines on running engine… also the ones that go out of the bobcat controller. So I tried at the end to connect directly 12v to the actuator motors for lift and tilt while operating. Tilt worked in one direction for a second and lift did not worked at all. I was able to notice a hydraulic pressure in the lines, but no movement at all!! Is there a blocking valve or something?! For now I will try maybe tomorrow or Monday to remove the actuators and do a mechanic control like I sow on a youtube video. I just need to do a job next week and will try to repair the ACS maybe later and check the actuators outside the machine.

 

[Bswwood]

Hello again, So I got the parts manual and was able to see how the linkage works on a non-ACS-machine … it is a non-electric control system that is very much different than the ACS system. No actuators and no pedal/hand electric to control with. This will not be very fast to do and I am not sure if the valves can be controlled "manual" with the actuators connected. I will go to the machine later and check. I now try to understand the schematic and to find a way to use the actuators without the ACS control. There are 5 wires that are connected to it: -4790 – forward connected to the ACS -4780 – backword connected to the ACS -2770 – ground -1630 – 5v support voltage that is also connected to the other actuator, the hand hall sensors and the pedals -4770 – a signal that is in the middle of 2770 and 1630… this is the signal from the position sensor or something. So I wrote this part this morning before I worked on the machine! Now the upgrade: I checked all electric options I had in mind. -Added 5V to the support line – no change -checked the max voltage (15,4V) and disabled the generator to be sure there is no overvoltage error -checked again the unshielded and shielded 12v lines on running engine… also the ones that go out of the bobcat controller. So I tried at the end to connect directly 12v to the actuator motors for lift and tilt while operating. Tilt worked in one direction for a second and lift did not worked at all. I was able to notice a hydraulic pressure in the lines, but no movement at all!! Is there a blocking valve or something?! For now I will try maybe tomorrow or Monday to remove the actuators and do a mechanic control like I sow on a youtube video. I just need to do a job next week and will try to repair the ACS maybe later and check the actuators outside the machine.

The best thing to do would be to repair ACS unfortunately. The machine can be converted to foot controls via linkage and the actuators would have to be removed so mechanical linkage can be hooked to valve spools. However the main controller will have to be reprogrammed to non-ACS or the control valve will remain locked. By the time all that is done it would have been cheaper to fix ACS. The actuators have 5 wires, 2 motor wires and 3 sensor wires. If you remove the actuator and look at the plug you will find pin numbers. Pin 1=sensor ground, pin 2=sensor signal, pin 3=sensor 5V input, pin 5= motor -dcv and pin 8= motor +dcv. The sensor in the actuator is a hall effect sensor and the motor works with PWM from the controller. If you try to control the actuator without PWM it will not only control the valve at full stroke but will burn up the motor very quickly. So it is not possible to run actuators without controller. Your valve should have a BICS lock valve that is released by the main controller and receiving inputs from the ACS, this is why you had pressure but no functions, you should also have spool locks but not perfectly sure because Bobcat was going thru lots of changes during that model year.

 

[Michael_S185]

The best thing to do would be to repair ACS unfortunately. The machine can be converted to foot controls via linkage and the actuators would have to be removed so mechanical linkage can be hooked to valve spools. However the main controller will have to be reprogrammed to non-ACS or the control valve will remain locked. By the time all that is done it would have been cheaper to fix ACS. The actuators have 5 wires, 2 motor wires and 3 sensor wires. If you remove the actuator and look at the plug you will find pin numbers. Pin 1=sensor ground, pin 2=sensor signal, pin 3=sensor 5V input, pin 5= motor -dcv and pin 8= motor +dcv. The sensor in the actuator is a hall effect sensor and the motor works with PWM from the controller. If you try to control the actuator without PWM it will not only control the valve at full stroke but will burn up the motor very quickly. So it is not possible to run actuators without controller. Your valve should have a BICS lock valve that is released by the main controller and receiving inputs from the ACS, this is why you had pressure but no functions, you should also have spool locks but not perfectly sure because Bobcat was going thru lots of changes during that model year.

Thank you for the replay Bswwood!! I will buy for sure a new ACS controller later, but I need to run the machine for some days now and with this Coronavirus I can't order or do anything at the moment. So I will today try to remove the actuators and disable the BICS valve. The linkage is easy to build with some welding. I don't have spool locks installed because it is an ACS machine (schematic). The BICS hydraulic lock was a very good idea! Thank you again! I thought there is something like that, but I had no more time for the repair last time. So the BICS hydraulic lock is with 12V and 9,8ohm in the schematic. I will try to give 12V with a switch and see what will happen. The valve should unlock. There are only two wires going down there. So this is my plan for now. I will write later and report.

 

[Michael_S185]

Thank you for the replay Bswwood!! I will buy for sure a new ACS controller later, but I need to run the machine for some days now and with this Coronavirus I can't order or do anything at the moment. So I will today try to remove the actuators and disable the BICS valve. The linkage is easy to build with some welding. I don't have spool locks installed because it is an ACS machine (schematic). The BICS hydraulic lock was a very good idea! Thank you again! I thought there is something like that, but I had no more time for the repair last time. So the BICS hydraulic lock is with 12V and 9,8ohm in the schematic. I will try to give 12V with a switch and see what will happen. The valve should unlock. There are only two wires going down there. So this is my plan for now. I will write later and report.

Hello again! I wrote this last week, but was not able to finish it: Yesterday was a good day with the project. I disconnected the actuators and the distance plates. The plates are holding the seals of the valves so don't try to run without them like I first tried! The plates should be on when you try to build your mechanic linkage. This part now is the new one: So in this plates are about 22,5mm cylinder wholes that the shaft moves in and out. The shaft is 12,5mm and there is a whole to fix with a little fixing shaft. I just took a pipe with 12,5mm inside and about 2,5mm walls and I made a 5mm whole like the one on the actuator. I also made a thin pipe with about 19mm inside and 22mm outside that should be an outside cylinder body that will not allow the fixing bolt in the first pipe to go out. You have to cut the pipe longer, so the inner pipe can move like a piston in it the whole way up and down. Rest work is some welding to make the linkage and is kind of individual work, but not hard to do. I was able to connect the one valve with a threaded rod to the right foot pedal. I made it this way so I can better build it out later and not need to cut it. The other valve is kind of tricky because you have a long way to go over the middle of the machine and you need to make everything very tight, so you don't lose any movement on the way to the valve. I actually was not able to make it work proper because of that and made a hand linkage on the right side so I can use the machine now. The rest will be done maybe in two weeks. The electric was very easy to do. The valve is on the down side of the pump and there go two wires to it. I took a 12V switched power for this one from one of the wires going to the ACS controller… You also have to unlock the foot pedals. For this I just used the switch for hand/food control. There is a 12V switched power there that you just need to connect to the foot lock with a short wire. The foot lock is actually good while you build your linkage so you always know when you are in the middle of the pedal way. That's it! Sorry for my bad English, but I hope to help some guys that have the same problem like me! I also now think about making an "easy way" to use the actuators, but this will be another topic! Thanks for the help!

 

[NinePine]

Hello again! I wrote this last week, but was not able to finish it: Yesterday was a good day with the project. I disconnected the actuators and the distance plates. The plates are holding the seals of the valves so don't try to run without them like I first tried! The plates should be on when you try to build your mechanic linkage. This part now is the new one: So in this plates are about 22,5mm cylinder wholes that the shaft moves in and out. The shaft is 12,5mm and there is a whole to fix with a little fixing shaft. I just took a pipe with 12,5mm inside and about 2,5mm walls and I made a 5mm whole like the one on the actuator. I also made a thin pipe with about 19mm inside and 22mm outside that should be an outside cylinder body that will not allow the fixing bolt in the first pipe to go out. You have to cut the pipe longer, so the inner pipe can move like a piston in it the whole way up and down. Rest work is some welding to make the linkage and is kind of individual work, but not hard to do. I was able to connect the one valve with a threaded rod to the right foot pedal. I made it this way so I can better build it out later and not need to cut it. The other valve is kind of tricky because you have a long way to go over the middle of the machine and you need to make everything very tight, so you don't lose any movement on the way to the valve. I actually was not able to make it work proper because of that and made a hand linkage on the right side so I can use the machine now. The rest will be done maybe in two weeks. The electric was very easy to do. The valve is on the down side of the pump and there go two wires to it. I took a 12V switched power for this one from one of the wires going to the ACS controller… You also have to unlock the foot pedals. For this I just used the switch for hand/food control. There is a 12V switched power there that you just need to connect to the foot lock with a short wire. The foot lock is actually good while you build your linkage so you always know when you are in the middle of the pedal way. That's it! Sorry for my bad English, but I hope to help some guys that have the same problem like me! I also now think about making an "easy way" to use the actuators, but this will be another topic! Thanks for the help!

Thanks for the update. Glad to hear you are getting it worked out.