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Komatsu PC88 E41 error - A slew error

Farmingosteo

New Member
Joined
Jul 12, 2020
Messages
2
Location
Hereford
Right.. this has been causing me so many issues. We had Komatsu engineers out to fix it. They were terrible in their approach and it cost a lot with no resolution.

My main issue is that hydraulic and electrical details supplied from komatsu are very difficult to find (good luck) so troubleshooting is also hard. Hence me adding this to try and help people out.

So I will describe my thought process and you can see if it helps you.

Firstly the solenoids for this action are based under the cab at the very front. Mine were both located on the right hand side of the manifold. Hydraforce the brand... 20Volt DC for some obscure reason... and imperial in size. These are not standard to hydraforce. Going direct will not help. Try komatsu or a breakers yards.

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So the E41 error is as far as i am aware an electrical error. But this needs to be confirmed so I recommend buying two solenoid commissioning magnets to suit. Solid state. Maybe 30 pounds but worth it. Air conditioning or plumbing companies sell these.

The error itself means that you can not slew the arm of the digger left or right. But this can be overridden with the switch behind the right hand side drivers armrest. There is a hidden switch there. engaging that for the short term will negate the e41 error. Short term being the important detail here as its activation will slow tracking and it is there really for safety so important... not a long term fix. One slew direction may now work using the foot pedal.. great.. take note.... meaning that this side of the circuit is fine. If neither directions works then i still may be able to help you but it may be the hydraulic circuit or a number of other things being the cause of the issue. If slewing right and left now both work.... then i cannot help you here, you will need to look deeper into the wiring as to what is causing this error, it may be a poor contact.

So these solenoid coils wear out. They are 20V DC rated but when i tested the actual voltage it read more like 26 to 27 Volt.... so that would be a likely reason for their degradation. At least in my machine. Check both coils DC voltage. if one is 0Volt then this could be a connection problem elsewhere.

When activated these coils activate the hydraulic circuit to allow the slew via the foot control. They do not actually slew the arm. Just open the circuit.

*****Before this test firstly unplug the existing solenoid coils as they can melt if not bolted to the heat sink peg.
Therefore as long as the hydraulic circuit is functioning fine and the solenoid peg is working we can see if we can get the slew working. If you have an e41 error and it is thought likely the solenoid coil then by using a single or two commissioning magnets (solid state) on the solenoid pegs and clicking up the error override switch this should lead to the foot switch working correctly. This will then mean you are likely looking at an electrical fault. Then.. if you are lucky enough to have one coil working you can remove one of the commissioning magnets and put in one of the potentially faulty/operational coils. test the slew again. If the slew works correctly using the one hydraforce coil (and one commissioning magnet on the other peg) then this is likely working fine. Then if it doesn't work using the hydraforce coil then this likely needs to be replaced.

It is worth doing all this as the coils are really expensive in the uk and i tried to source them in the usa but it was almost impossible as the sizing is not standard.

I hope this is of some help. If it is please write so as it will save me thinking i am talking to myself. Remember the commissioning magnets are also not long term.. simply for testing. The safety systems put in place by Komatsu are very thorough and important so should not be bypassed when in normal operation.
Komatsu diggers are great pieces of kit.. top pieces of kit. I just wish the technical help was more open.
 

John C.

Senior Member
Joined
Jun 11, 2007
Messages
12,865
Location
Northwest
Occupation
Machinery & Equipment Appraiser
The model Dash number or the serial number is necessary before anyone can try to help you. Do you have a service manual? Do you have prior working experience on excavators? Are you aware that there is a swing brake system?
 
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