Bobcat M1016 (10-16) Fault Code: Hydraulic Charge Filter Not Connected
Also shown on the panel as 10-16
Hydraulic Charge Filter Not Connected · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
M1016 (panel code 10-16) sets when the Bobcat gateway controller sees an open circuit for 30 seconds on the hydraulic charge filter switch with the key switch in run/enter on. It usually points to a wiring, grounding, or switch problem, not necessarily a clogged filter, since the switch is normally closed and opens only when pressure difference across the filter reaches a critical level or when the circuit itself fails.
Medium severity. M1016 does not by itself indicate loss of hydraulic function, but if the switch is opening because the charge filter is actually restricted, hydraulic charge pressure to the fan drive circuit can suffer. Treat it as a diagnose-this-shift item rather than an emergency, unless other hydraulic performance symptoms show up alongside it.
What does Bobcat error code M1016 mean?
M1016 is a Bobcat gateway controller fault tied to the hydraulic charge filter switch, which lives on the back of the hydraulic fan filter assembly. This is a one-wire, normally closed switch that grounds through the filter housing itself (case grounded). It opens when the pressure difference across the filter reaches a critical level, which is meant to warn you the filter is restricted.
The code sets when the controller detects the circuit open for 30 seconds with the key switch in run/enter on. Because the switch is normally closed, an open circuit can mean either a genuinely restricted filter or a wiring, grounding, or connector fault that mimics that condition electrically.
The code can appear while the engine is already running if the open condition existed before the engine was started. This matters for diagnosis: an M1016 that shows up right at key-on is worth checking before you assume the filter is the culprit.
Common causes of M1016
- Poor grounding of the hydraulic charge filter switch through the filter housing (case ground path).
- Faulty hydraulic charge filter switch.
- Signal wire 3440 open (breaks continuity between the switch and the controller).
- Incorrect programming of the gateway controller.
- Faulty gateway controller.
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, the hydraulic charge filter switch connector, or the mainframe harness.
- Intermittent fault: if the code is not active at the time of testing, the root cause may not be identifiable right away. Likely contributors in that case are loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these.
How to troubleshoot Bobcat M1016: first checks
- Confirm the key switch is in run/enter on and check whether the code is currently active or was only stored, since an intermittent code may not reproduce on demand.
- Inspect the hydraulic charge filter switch connector and the mainframe harness connector at the gateway controller for moisture, corrosion, or pins that have pushed back out of their sockets.
- Check the ground path from the switch through the filter housing, since this switch is case grounded rather than using a dedicated ground wire; a poor housing-to-frame ground will read the same as a switch fault.
- Trace signal wire 3440 for continuity between the switch and the gateway controller, looking for chafe points, pinches, or corrosion along the mainframe harness.
- Test or swap the hydraulic charge filter switch itself if wiring and grounding check out, since the switch is a low-cost, common failure point.
- If wiring, ground, and switch all check good, verify the gateway controller's programming and consider controller-level diagnostics.
How the code clears
This code is self resetting. No separate clearing step is listed beyond making the repair; once the open circuit condition is corrected, the code should clear on its own.
Affected models and serial ranges
M1016 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, SN A3NW11249-99999 |
| S750 | SN A3P211001-299999 |
| S770 | 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 M1016 mean?
It means the gateway controller detected an open circuit for 30 seconds on the hydraulic charge filter switch while the key switch was in run/enter on. The switch is normally closed and mounted on the hydraulic fan filter assembly, so an open reading usually means either a real filter restriction or a wiring/ground/connector fault.
Does M1016 mean I need to change the hydraulic charge filter?
Not necessarily. The switch opens when pressure difference across the filter reaches a critical level, so a clogged filter is one possible cause, but poor grounding, a bad switch, an open signal wire, or corroded connectors can trigger the same code without the filter being the problem.
Can M1016 show up while the machine is already running?
Yes. If the open circuit condition was present before the engine started, the code can appear even after the engine is running, not just at key-on.
Is it safe to keep operating with an M1016 code active?
There's no listed severe consequence tied directly to the code, but since it relates to hydraulic charge filter condition, it's best to diagnose it during the same shift rather than ignore it, especially if you notice any other hydraulic performance changes.
Will M1016 clear itself after I fix the problem?
Yes, it's listed as self resetting. Once the open circuit is repaired, whether that's the switch, the ground, the wire, or the connector, the code should clear without a separate reset procedure.
What is signal wire 3440 and why does it matter for this code?
Wire 3440 is the signal wire between the hydraulic charge filter switch and the gateway controller. If it's open anywhere along the mainframe harness, the controller will see the same open circuit condition as a bad switch or a genuine filter restriction.
Which Bobcat machines can show code M1016?
It applies across a range of Bobcat skid-steer and compact track loader models including the S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770 lines, plus the T870.