Bobcat D7528 (75-28) Fault Code: Right Swash Plate Out of Position
Also shown on the panel as 75-28 · Also called Drive Right Swash Plate Out of Position, Right Swash Plate Out Of Position
Right Swash Plate Out of Position · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
D7528 (panel code 75-28) sets when the drive/drive plus controller sees the right swash plate sitting opposite of the commanded position, or not reading in the neutral range of 2.08 to 2.92 volts when neutral is expected. The engine shuts down when this code triggers. It affects Bobcat S510 through S770 and T550 through T870 skid-steer and track loaders equipped with the drive/drive plus system.
High severity. D7528 forces an engine shutdown as soon as the drive/drive plus controller detects the fault, so the machine stops working immediately. It is not a code you can ignore or drive through. Treat it as a stop-and-diagnose issue before returning the machine to work, since it points at a hydrostatic drive control problem that affects how the machine moves.
What does Bobcat error code D7528 mean?
D7528 means the drive/drive plus controller on your Bobcat loader has found a mismatch between where it told the right swash plate to go and where the swash plate sensor says it actually is. The swash plate inside the right drive pump controls the direction and rate of oil flow to the right drive motor, so its position basically sets your right-side travel direction and speed. If the sensor feedback says the swash plate is opposite of command, or it will not read in the neutral window when the controller expects neutral, the controller cannot trust that side of the drive system and shuts the engine down as a protective measure.
The swash plate sensors sit at the bottom of the pump and are keyed to the swash plate itself, so they physically move with it. They get battery voltage supplied through the gateway controller, and their output signal is designed to range between 1.0 and 4.0 volts depending on swash plate position. The drive/drive plus controller reads this signal continuously once PTOL is enabled and the engine is running, watching for it to match the commanded position and for it to sit inside 2.08 to 2.92 volts whenever neutral is commanded.
Because this fault shuts the engine down rather than just throwing a warning light, it is considered a functional safety trip. The system would rather stop the machine than let it move unpredictably on one side.
Common causes of D7528
- Contamination inside the hydraulic system affecting pump or sensor operation.
- Hydraulic pump not physically centered.
- A failed or out-of-range right swash plate sensor.
- Right drive solenoids not properly connected.
- Right forward drive solenoid or right reverse drive solenoid shorted to supply voltage or to ground. Check for additional codes D7545, D7546, D7555, D7556, and D7574 when this is suspected.
- A fault in the drive/drive plus controller itself.
- Moisture, corrosion, or pushed-back pins in the drive/drive plus controller connectors, the swash plate sensor connector, or the AWS/SJC wire harness.
- Intermittent conditions where the fault is not present at the time of testing. In these cases the cause may not be identifiable right away, and probable contributors include loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these.
How to troubleshoot Bobcat D7528: first checks
- Confirm the conditions needed for the code to be active: key switch/run-enter on, PTOL enabled, and engine running. If any of these are not met, the controller will not be evaluating this circuit.
- Inspect the swash plate sensor connector at the bottom of the right pump, along with the drive/drive plus controller connectors and the AWS/SJC wire harness, for moisture, corrosion, or pushed-back pins.
- Check the right drive solenoids for proper, secure connection, and inspect wiring for the right forward and right reverse drive solenoids for signs of a short to supply voltage or to ground.
- Verify the swash plate sensor signal is within the expected 1.0 to 4.0 volt output range and reads within 2.08 to 2.92 volts when the swash plate should be in neutral.
- Check whether the hydraulic pump is physically centered, and inspect the hydraulic system for contamination that could affect swash plate or sensor movement.
- If no fault is present at the time of testing, treat it as a possible intermittent connection issue and recheck all harness connectors and pins in the circuit rather than assuming the code was a false trip.
How the code clears
Once the repair is complete, the listed procedure is to cycle power. No separate clearing step is listed beyond powering the machine off and back on after the underlying cause has been corrected.
Affected models and serial ranges
D7528 appears in our records across 16 Bobcat models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| S510 | SN A3NJ11001-99999, SN A3NK11001-99999, SN ATZC11001-ATZC99999 |
| S530 | SN A7TV11001-99999, SN ATZD11001-99999 |
| S550 | SN A3NK11001-A3NL99999, SN A3NM11001-99999 |
| S570 | SN A7U711001-799999, SN A7U811001-899999 |
| S590 | SN ANMN11001-99999, SN ANMP11001-99999 |
| S630 | SN A3NT12370-99999, SN A3NU11001-11111, SN A3NU11112-99999 |
| S650 | SN A3NV11001-13098, SN A3NV13099-99999, SN A3NW11001-11248 |
| S750 | SN A3P211001-299999 |
| S770 | SN A39511001-99999, SN A3P411001-99999 |
| T550 | SN A7UJ11001-AJZV12276 |
| T590 | SN ALJU11001-999999, SN B37811001-999999, SN B3Z711001-999999 |
| T630 | SN A7PU11001-11663, SN A7PU11664-99999 |
| T650 | SN A3P012214-099999, SN A3P111242-199999 |
| T750 | SN ANKA11001-A99999 |
| T770 | SN A3P811001-899999, SN A3P911001-999999 |
| T870 | SN A3PG11001-99999, SN A3PH11001-99999 |
Frequently asked questions
What does Bobcat code D7528 mean?
It means the drive/drive plus controller detected that the right swash plate position is opposite of what it commanded, or the swash plate sensor did not read in the neutral range of 2.08 to 2.92 volts when neutral was expected. This causes an engine shutdown.
Why did my Bobcat loader shut off the engine with D7528?
The drive/drive plus controller shuts the engine down as soon as it detects this mismatch on the right swash plate, since it cannot verify the right side hydrostatic drive is responding correctly. This is a built-in protective response, not a random stall.
What conditions have to be present for D7528 to set?
The key switch/run-enter must be on, PTOL must be enabled, and the engine must be running. The controller only monitors the swash plate sensors under these conditions.
Could a bad connector cause D7528 instead of a failed sensor or pump?
Yes. Moisture, corrosion, or pushed-back pins in the drive/drive plus controller connectors, the swash plate sensor connector, or the AWS/SJC wire harness are all listed causes, and these are often cheaper and faster to fix than a sensor or pump replacement.
Are there other codes I should check alongside D7528?
If a shorted right forward or right reverse drive solenoid is suspected, check for additional codes D7545, D7546, D7555, D7556, and D7574, since these can appear alongside D7528 and help narrow down the circuit at fault.
How do I clear D7528 after I fix the problem?
Cycle power to the machine after completing the repair. No separate clearing procedure beyond a power cycle is listed for this code.
What if the code doesn't show up when I test the machine?
If D7528 is intermittent and not active during testing, the exact cause may not be identifiable at that time. Probable causes in these cases include loose connections, corrosion, pushed-back pins, the controller, or the wire harness, so a careful recheck of all connectors in the circuit is worthwhile even without an active fault.