We are having a problem with the steering on our 980k. Code is E258-3. no steering with command. Not really sure where to look. We replaced the steering spool position sensor. no luck ohm on steer solenoids are 5.5 and 5.7 ohm on pilot supply solenoid 38.2 (marginally out of spec.) We are getting readings from both steering cylinder position sensors. We are also see the joystick telling the machine to turn. The joystick is unresponsive and the machine won't turn on startup. if you hold the joystick to one side or the other it will catch and start working. This is when we get the code. If it were hydraulic it could be described as having air in a line at start. Both primary steering system steer solenoid current percentages are where i think the problem lies. These are 0 when the code is displayed and when trying to turn. I think they are supposed to have minimal voltage even with the stick neutral. they will jump from 0 to 50% with no input on startup. I don't know if there is something that triggers the computer to send the voltage to these or what is upstream to look at. We have minimal access with et and I am not well experienced with how to navigate et. Any help or direction would be great. Cat says they can't look at it for 2 weeks....
Just to be safe and avoid anyone trying to look up information on SIS how about a full S/N for this loader? Quick look on SIS seems to show at least three S/N prefixes for 980K!
Your right. I'm so flustered over the two week wait for service it skipped my mind. W7k00623
E258 (3) No Steering Detected With Command Given. Immediate safe shutdown required. Travel speed is greater than 9 km/h (5.6 mph) and no articulation movement is detected when commanded. ALSO - Activated when the Machine ECM is controlling the Secondary Steer System and Articulation Cylinder movement is not detected when joystick command is present. Comment - I don't think your machine is equipped with a Secondary Steering system. Troubleshooting flow chart attached. First thing is that these sensors do not give a current or a voltage signal to the ECM. They signal they supply is known as PWM (Pulse Width Modulated) and requires a DMM capable of measuring Duty Cycle in order to measure the sensor output. Yes they are powered from the ECM by 8v and grounded back to the ECM, but what you see on ET is the sensor Duty Cycle signal expressed as a percentage. Generally position sensors for joysticks and cylinders will register a signal of around 50% when the sensor is in the central position, around 0% when the sensor is all the way over to one side, and around 100% when the sensor is all the way over the other side. So long as the steering is approximately in the straight ahead position I would expect the sensors for both the joystick and each of the steering cylinders should register around 50% Duty Cycle as soon as the key switch is energized.
So I am not the best with et. I can't seem to be able to activate the manual secondary steering system... The primary steering valve spool disp signal voltages are 2.476-2.480 with KOEO and with KOER arm up and arm down. When turning the signal voltage goes as low as 1 and as high as 4. seems like there is some room for improvement here but it is hard to move the lever so I am not trying to break it.... The steering valve spool position sensor was replaced today. I do not know if the spool movement was checked we will pull it back apart tomorrow to double check. Could you describe how to do the secondary steering test also the steer system solenoid calibration test. just where to find it would be great. I think we have et2015
The secondary system does work I can see it activate in et. But without the test I don't know if it will trigger the same code.
Before you go ripping into valves, solenoids, or whatever don't you think it might be an idea to try working through the torubleshooting chart that I posted above and see where it leads you..?
Ideally yes. Unfortunately with limited experience on et and being unable to switch to manual secondary steering I can only do so much. I have worked through some of the chart already and most keep leading to a stuck or faulty spool sensor.
My apologies. If you had said that you were working through the chart and got stuck at a certain point my answer would have been somewhat different. You can't "switch to" secondary steering. All you can do is test the system. This is done from the Monitor Panel, not using ET. It's also worth noting that the Secondary Steering function is supposed to be tested weekly by the operator. How much do you want to bet nobody even knows how to test it..? Test procedure attached. Do me a favour. Download a pdf copy of the Product Status Report and post it up. You will find the link to it in the drop down menu under "Information" when you have ET connected to the machine. There does not seem to be any calibration procedure for the steering system solenoid, not one that I can find anyway.
Thanks, I have worked through most of the chart and landed on 3 possibilities. 1 a steering spool valve hanging up. I'm not sure this is likely 2 possible open or high resistance in spool sensor circuit. I don't think this is likely either. 3 possible steering pump failure. I think this is the most likely. could lead back to 2 since it is a piston pump. The secondary steering system works as it should with no codes. This is what is making me lean toward low pump pressure since the secondary system takes the oil from the brakes and fan. Is there a way to check the pump pressure in et? I would think if it were low pump pressure I would have another code? I will get a status report shortly.
product status report
Here's the test procedure for the steering pump. Note that there are three tests - High Pressure Stall, Margin Pressure, & Low Pressure Standby. Also there is the pump backup relief valve to check/adjust. I'll have a look at the PSR and see if anything obvious jumps out and hits me.
Since we have no movement from the primary steering system when the joystick is moved how can we be sure the pump receiving signal to stroke? Not sure if this makes sense... I don’t want to put a pump on if it turns out the signal was the issue
Even if the pump is not receiving a signal to upstroke it should still achieve Low Pressure Standby which is the last test in the document I uploaded above. I'd start the pump pressure testing with that test and see where it leads you. Here's an interesting thing I found on Page 4 of the PSR. According to this the Secondary Steering system (which I said earlier I didn't think the machine had) is listed as "Not installed". The usual reason for this parameter to be set like this is that the machine is not equipped with that attachment. To settle the debate once & for all does the machine have the pump shown in blue mounted on the back side of the transmission drop box.? See below.
It does not have the backup pump. the low pressure pump test had about 600 psi. how can we isolate he primary system from the secondary to check the pressure. I assume the pump supply port when it goes to the secondary system will still be pressurized by the brake and fan circuit. I’m not the best when it comes to the newer equipment diagnostics
If it does not have that pump then it does not have a secondary steering system. Does the steering respond to the joystick at all, even though it generates the E258 Code.?
Just following along on this one as they had a 980K at the quarry that they got a couple years before I retired. Sometimes Cat can make things a bit confusing with terminology if you don't work on these machines everyday. Also some of the trouble shooting information is written to include all the possible options, just try following the information on an older 3306 fuel system that can send you down a rabbit hole fast if you are not careful!
Exactly. And if the machine does not have a certain attachment, such as the secondary steering in this case, then you just move past all the testing relating to that system in the diagnostic procedure.
When I first move the joystick there is a delay in response. About 3-5 seconds. Then the code comes on and the machine will start to turn. It lights up secondary steering on the panel. It will continue to alarm but it will turn. I’m assuming it is using the secondary steering solenoids? I have followed the diag chart and keep coming back to spool valve movement or contact cat. we replaced the spool valve sensor. The new part looked different than the old but cat says it’s a redesign... I will get both part numbers and post.
Old part 341-0824 New part 461-2544 Spool position sensor. This is what it seemed like the problem should have been as far as I can tell from the way the system works it doesn’t see this spool moving? the parts looked different but cat says they are the same...
The new part is a direct replacement (and an improvement) over the old one.
If the steering moves, albeit with a delay, try doing the High Pressure Pump Stall test.
It can light up the secondary steering icon on the panel all it likes, with it being shown as "Not installed" in the Machine Configuration screen, there will be no secondary steering - probably also due to the lack of a pump that provides pressure for the secondary steering system. Note even if that pump was installed it would only rotate when the machine is moving because it is driven off the transmission output gear group...........
Maybe I’m confused. I thought the secondary steering even without the pump was functional? Does it not take the hydraulic supply from the fan and brake circuit instead of the steering pump? I’m assuming the fan and brake circuit run off the main hydraulic pump? essentially that secondary pump that this machine does not have would be a third way of getting hydraulic fluid? when in primary mode the computer looks at the joystick and spool valve sensor. If it doesn’t see what it likes it switches to looking at the joystick and cylinder position sensors?
No it does not. The fan/brake/implement pilot circuits are the only ones that run from the "Fan Pump". the steering circuit is separate and not connected in any way. I can see that there is a lack of consistent nomenclature in the description of components and operation of the Steering System. 1. In some parts the L & R Solenoid valves are referred to as Primary and Secondary [To me this is confusing]. In others they are referred to as the Primary and Redundant solenoid valves. I will refer to the Primary Solenoid Valves as the #1 Solenoid Valves and the Secondary/Redundant Solenoid Valves as the #2 Solenoid Valves to try to make it clearer. 2. IMHO it would be better to use the terminology "Primary Steering Control", "Backup Steering Control", and Secondary Steering. As I understand it this is how the Steering Controls work: - Primary Steering Control - Signals from the Implement ECM to the #1 Left & Right Solenoid Valves. Backup Steering Control - (automatically activated if a fault is detected in the Primary Steering Control electronic feedback loop) Signals from the Machine ECM to the #2 Left & Right Solenoid Valves. The oil supply for both Primary and Backup Steering control is supplied by the steering pump. Secondary Steering - (on machines so equipped) a transmission-mounted pump that provides an oil supply via a shuttle valve to the steering system in the event of a failure of the primary oil supply. If Secondary Steering is activated it is controlled by the Machine ECM and the #2 Left & Right Solenoid Valves.
As I recall the ground power steering pump is a supplemental source of flow to the main steering system. The issue way back when was that when engine RPM dropped down while the machine was coasting down hill, the main steering system flow also dropped and the ground power pump supplied supplemental flow to keep the machine steering at a safe flow and power level. I have had a couple of machines with those systems and just simply hated them. The issue is that the engine RPM has to be raised in order to get the machine to steer at all when sitting still. The backup steering systems I am familiar with have an electric driven pump that automatically comes on with a loss of flow from the gear driven steering pump.
John, the pump on the drop box is ground speed driven. However the only way that this pump would ever supply flow to the steering circuit would be if the supply from the principal steering pump failed completely - think engine failure. The only function of the secondary steering pump is to supply oil for the steering system to enable a machine to be safely brought to a stop and that's it. It is a secondary steering pump, not a supplemental one, so the issue of minimum engine RPM to get the machine to steer when not moving does not arise.
Got print of the hydraulic schematic? I’ve had two other machines with that system and guess what, the steering system won’t work right without it.
Here's the schematic. Problem is that the Secondary Steering system is an attachment, not a standard fitment. So somehow the steering system has to be able to work without that pump in any machine where it's not installed.
We replaced the pilot supply solenoid and that fixed the problem. I'm really surprised. Spec called for 33.8 +-1.7 and our reading was 38.2. I expected it to be somewhat higher as the oil temp and ambient temp was higher than suggested.
Funnily enough in the SysOp the first thing that happens to "energize" the steering system via the Implement ECM after all the required conditions are met (operator in seat, armrest down, engine running, trans in neutral, park brake on, zero ground speed) is that the steering pilot solenoid energizes. I would suspect that because the coil resistance on the steering pilot solenoid valve was only slightly higher than spec and had not gone completely open circuit that's why it did not throw up a Diagnostic Code. I think it is referred to as Primary Steering Disable Solenoid (CID 2177) in the Code list but wouldn't swear to it. Good to hear you got it sorted.