Hi there. I have a Cat 246C skid steer that the left drive motor doesn't drive after being repaired. The original problem was that the left drive motor had a leaking seal. But was otherwise working/driving. The left drive motor was removed, repaired and replaced. Now the left drive motor won't drive. However the right drive motor works fine. I am confident that the seal repair was done correctly. The following has been checked and ok. All left side drive motor hoses reconnected correctly. Hydraulic oil full, (all other hydraulics working fine), left drive motor bled, all fuses, relays and wiring harnesses checked. ECM fuses checked. Both side hydraulic motor speed sensors checked and swapped from left to right motors. Left side Forward/reverse joystick removed and wiring harnesses continuity checked. Still no drive to left side drive motor, with right side still working. My question is do I need to calibrate the left drive motor/ speed sensor etc or some other function by using Cat ET software which I don't have at the moment. The only active diagnostic code is E875 - 2 which I believe is a low voltage issue. This code goes after the machine is jump started. I have various other logged codes as well, which I don't know what they are. ? E391-1, E875-1, E361-3, E875-3, 2476-3, 2474-3, 367-3, 2474-4, 2475-4, 2476-4, 2477-4, 2212-5, 598-5, 354-6, 2687-8 Any help or advice appreciated as what I should do to diagnose the problem. Thankyou..
No you don't. Motors either drive or they don't. E875-2 is low voiltage. Activates when the engine is running and battery voltage is 12.25 VDC for 2 seconds. You really need to investigate that at some point altough TBH I'm not sure it's related to your issue. Question: When you try to drive the LH motor do the hydraulic hoses connected to it give any appearance that they are under pressure.? You should see them jerk or jump when the joystick is moved. Try swapping the connections on the joysticks between LH & RH motors then use the LH joystick to drive the RH motor. That should prove if the joystick is working OK or not. I assume that your machine Serial Number is JAY-something.
These Codes are all related to the joystick position sensors.
Hi Nige. Thankyou for the prompt reply and advice. The LH motor hoses don't jump or jerk at all, they are completely dead, with no pressure. Just a dribble from them when bleeding the lines. Where/which connections would be the easiest to swap ? at the LH joystick harness (if so which wires) or at some other location ? If those relevant codes are joystick related are they active codes or logged, and could it indicate a faulty position sensor ? Is there a test sequence for the joystick position sensor that I could do as well ? Yes the machine is a 2011 JAY Thankyou
Are you reading the Codes from the supplementary panel on the right side.? If so that should indicate if they are Active or Logged. The fact that you get no oil out of the hoses seems to point at the joystick(s) but here’s the thing. The RH side of the machine drives but some of those Codes you listed are for the RH joystick, so that indicates they are likely to be Logged.
Thankyou. Yes I am reading the codes from the supplementry panel on the right side within the cab. The right side joystick codes appeared after I removed / checked the wiring harness. Repaired some open circuit wires from the joystick buttons that had rubbed on the joystick shaft under the rubber boot. However the position sensor harness wiring showed no faults / problems Is there a multimeter test I can do on the position sensor ? What wires should I swap to use the RH drive input to drive the LH ?
That makes sense now. The joystick position sensors are PWM-type and their output is shown as a % signal. To read them requires aDMM equipped with a Duty Cycle function. However you should also be able to read the signal from each fore-aft or side-to-side joystick sensor on the same RH panel that you used to show the Diagnostic Codes. Note that Active Codes appear in Service Mode 1 and Logged Codes appear in Service Mode 2. That's how you can tell what's Active and what's not. To check the joystick PWM signals you need to be in Service Mode 6. See Page 3 of the attachment.
Thankyou. I will check the LH joystick % measurements as advised in Mode 6. Questions in advance before I get to check this in a few days time. Should it read 100% on all 4 axis, or what should it read ? Am I able to calibrate the joystick from that point and method ? Would an inconsistent % readings indicate a faulty position sensor that requires replacing ? Thankyou
With either joystick in the centre (neutral) position both the X-Axis and Y-Axis sensors should read 0%. If you move the lever in any direction the applicable sensor reading should increase in a smooth fashion from 0% up to possibly 100% at full lever movement. I'm not sure if it will show + or - but max travel one way should be +100% and the other way should be -100%. As a suggestion I would try the RH joystick first (because the machine drives on that side) and then compare the results you get from it with those from the LH side. No. There is no calibration of those sensors. They either give correct readings or they don't. The typical symptom of a failed sensor is that it maintains a certain fixed % output reading whatever position the joystick is moved to. Yes, and unfortunately the only way to replace sensors is by replacing the complete joystick base.
Thankyou that is good advice that I should be able to work with to hopefully diagnose the problem. I will get back to it next week and keep you posted.
Nige, your wealth of knowledge is immeasurable!! Thanks so much for helping out here!!
After dealing with a C series joystick issue myself, I've decided someone could make a boatload of money by making those sensors aftermarket. It's such a small part of the joystick base and 4 screws to replace once you have the joystick out. Replacing the entire base seems silly.
Hi Nige. I have now tested both left and right joysticks by using the test function in service mode 6 as advised. They both have 0% in centre/neutral position and 100% in x and y axis. From this test I am of the opinion that the joystick sensors and wiring harness are good all the way to the ECM. Is this correct ? My next test is to pressure test the left motor park brake hose port to ensure the park brake is being released. What pressure should I get there when activating the park brake ? Then I will pressure test the left motor servo pressure port. Should this be pressurized when joystick is activated to turn left ? What pressure reading should I get ? Any further help and advice appreciated..
I am pretty certain that test rules out the joystick as a potential cause. I don't see a spec anywhere. Try testing the RH one first and see how the LH one compares. No idea unfortunately. Hopefully someone else will chime in.
I have now got 2 Active Codes 2685-8 and 2686-8 which apparently are Left drive motor speed sensor related indicating abnormal frequency pulse width or period. As I have swapped the left and right speed sensors with no improvement, I now suspect the wiring harness from the left speed sensor to the ECM. Can you advise of a diagnostic test procedure including wire colour and ECM pin numbers and expected DMM readings. Any help and advice appreciated. Thankyou
Here are the diagnostics for the two Code you have. A word of caution. These Codes will not change from Active to Logged unless the motor moves a certain number of rotations (I'm not sure how many). So you may be chasing a red herring. From the procedure - "If this diagnostic code is active, the ECM will keep the code active until a good sensor signal is observed by the Machine ECM. This means that the drive motors must be moved in order for the Machine ECM to determine if the active code can be cleared ."
I have a question I have this problem and did that procedure everything tested out good I ran new wires for the sensors anyways and still no good results I had gotten it to run good for 5 minutes after installing a new drive motor
Address Low Voltage Issue (E875-2): Since E875-2 indicates a low voltage issue, ensure your machine's battery and charging system are in good condition. Correct this issue before proceeding. Check Wiring and Connections: Recheck all wiring and connectors related to the left drive motor for any damage, loose connections, or corrosion. Pay attention to the ECM connections. Diagnostic Software (Cat ET): If possible, obtain Cat ET software to perform a diagnostic scan. This software can help identify specific faults and provide guidance on resolving them. It may also enable you to clear any fault codes that could be affecting operation. Sensor Verification: Ensure that all sensors, especially the left-side hydraulic motor speed sensor, are functioning correctly. Swap sensors between left and right sides to see if the problem follows the sensor. Consult Documentation: Refer to your equipment's user manual or service documentation for troubleshooting and calibration procedures specific to your machine. Professional Inspection: If the issue persists, consider seeking assistance from a certified Cat technician who can use diagnostic tools and expertise to pinpoint and rectify the problem. Recorded Fault Codes: Investigate the other logged fault codes (E391-1, E361-3, etc.) to determine if any are related to the left drive motor issue. Address these as necessary. Hope helpful.
Would you like to expand a bit, starting with a Serial Number, then to the symptoms, what Active Codes you have, and what you have done so far.
Hi recently joined the forum I also have had this problem left drive motor had a leak working perfectly before comes up as speed sensor swapped them over no go. Just seeing if you diagnosed the machine that had the issue.
Please supply a machine Serial Number and tell us exactly what Codes you have. This thread was last active 2 years ago, so starting from scratch makes more sense.