Bobcat D7517 (75-17) Fault Code: Left Swash Plate Not in Neutral
Also shown on the panel as 75-17 · Also called Drive Left Swash Plate Not in Neutral, Left Swash Plate Not In Neutral
Left Swash Plate Not in Neutral · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
D7517 (panel code 75-17) sets when the drive controller sees the left swash plate sensor outside the neutral range of 2.08 to 2.92 volts at system start up with the key switch on and PTOL enabled. When it sets, the engine shuts down and it will not run until the fault is corrected.
High severity. D7517 shuts the engine down at start up and blocks operation, so the machine cannot be used until the cause is found. It is not a mid-operation runaway hazard since it only triggers at start up, but it is a hard stop for productivity and should be diagnosed before returning the machine to work.
What does Bobcat error code D7517 mean?
D7517 is a Bobcat drive controller fault that fires when the left swash plate position sensor reports a voltage outside the neutral window of 2.08 to 2.92 volts while the drive controller is checking swash plate position at start up. The Press To Operate Loader (PTOL) function must be enabled for this check to run.
The swash plate sensor sits at the bottom of the hydraulic pump and is keyed to the internal swash plate, so its voltage output tells the drive controller exactly where the plate is sitting. The sensor gets battery voltage from the gateway controller, and its normal output signal range is 1.0 to 4.0 volts. If the reported voltage falls outside the neutral band when the controller expects neutral, D7517 sets.
This code is a start-up-only check. It does not set during normal driving or operation, only when the machine is first powered up and the controller verifies the pump is centered before allowing travel. When it does set, the engine shuts down as a protective measure.
What triggers a Bobcat D7517 code?
D7517 sets when, with the key switch/run-enter on and PTOL enabled, the drive controller checks the left swash plate sensor at system start up and finds its voltage outside the neutral range of 2.08 to 2.92 volts (against a normal sensor output range of 1.0 to 4.0 volts).
Common causes of D7517
- Contamination of the hydraulic system affecting pump or sensor operation.
- Hydraulic pump not physically centered.
- Faulty left swash plate sensor.
- Faulty drive controller.
- Moisture, corrosion, or pushed-back pins in the drive controller connectors, swash plate sensor connector, or SJC wire harness.
- Intermittent connection issues: loose connections, corrosion, pushed-back pins, controller faults, or wire harness problems, alone or in combination, which may not show up if the code isn't active during testing.
How to troubleshoot Bobcat D7517: first checks
- With the key on and PTOL enabled, check for stored or active codes and note whether D7517 is currently active or was only logged historically, since intermittent faults may not reproduce on demand.
- Inspect the drive controller connectors, the left swash plate sensor connector, and the SJC wire harness connectors for moisture, corrosion, or pushed-back pins.
- Verify the left swash plate sensor's supply and output voltages fall within the expected 1.0 to 4.0 volt signal range and check whether it reads inside the 2.08 to 2.92 volt neutral band when the pump is actually centered.
- Check the hydraulic pump for signs it is not physically centered, and inspect the hydraulic fluid for contamination.
- If wiring and sensor readings check out, consider the drive controller itself as a possible cause.
How the code clears
Cycle power after the repair is complete. No separate clearing step is listed beyond cycling the key switch off and back on.
Affected models and serial ranges
D7517 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 D7517 mean?
It means the drive controller found the left swash plate sensor reading outside the neutral voltage range of 2.08 to 2.92 volts during the start-up check, which happens only when PTOL is enabled and the key is on.
Why did my Bobcat shut down with D7517?
D7517 forces an engine shutdown as a safety measure when the left swash plate sensor isn't in the neutral range at start up. This is a start-up-only check, it will not appear mid-operation.
What is the panel display code for D7517?
The numeric panel form is 75-17.
What causes the left swash plate sensor to read out of range?
Possible causes include hydraulic system contamination, a pump that isn't physically centered, a bad swash plate sensor, a faulty drive controller, or moisture and corrosion in the drive controller, sensor, or SJC harness connectors.
How do I clear D7517 after repair?
Cycle power (key off, then back on) once the repair is complete. No other clearing procedure is listed.
Which Bobcat models can show D7517?
It applies to S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770 skid steer and track loader models, along with T870.
The code isn't active when I test it, what should I do?
If D7517 is intermittent and not active at the time of testing, the exact cause may not be found immediately. Focus on checking for loose connections, corrosion, pushed-back pins, the controller, and the wire harness, since any of these alone or combined can cause an intermittent fault.