Bobcat M0909 (09-09) Fault Code: Fuel Level Low
Also shown on the panel as 09-09 · Also called Fuel Level Too Low
Fuel Level Low · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
M0909 (panel code 09-09) means the gateway controller has detected a low fuel level for 30 seconds with the key switch in run/enter. It usually just means the tank is low, but it can also point to a fuel level sensor or wiring problem on wire 3100 or 3180.
Medium severity. This code is mostly informational when it reflects an actual low tank, but running the machine dry can cause fuel system problems and unexpected shutdown mid-job. Treat it as worth checking before you keep working, not an emergency stop.
What does Bobcat error code M0909 mean?
M0909 (also shown as 09-09 on the panel) is set by the gateway controller when it sees a low fuel level signal for 30 seconds while the key switch is in the run/enter position. The controller supplies 12 volts to the fuel level sensor on wire 3100 or 3180, depending on the model, and reads the voltage coming back from that sensor.
The fuel level sensor works as a variable resistor: as fuel in the tank drops, the sensor's resistance goes up. The gateway controller interprets that rising resistance as a falling fuel level, and once the signal stays in low-fuel range for the full 30 seconds, it sets M0909.
In most cases this code is doing exactly what it is designed to do: telling the operator the tank is genuinely low. But because the code is based on a sensor signal and wiring circuit, the same code can appear if the sensor or its wiring is faulty even when the tank is not actually low.
What triggers a Bobcat M0909 code?
The gateway controller sets M0909 when it detects a low fuel level signal for 30 seconds continuously, with the key switch in the run/enter position. The controller supplies 12 volts to the fuel level sensor circuit on wire 3100 or 3180 and monitors the return voltage; rising sensor resistance as fuel drops is read as a falling fuel level.
Common causes of M0909
- Fuel level is actually low in the tank.
- Faulty or failing fuel level sensor.
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, the fuel level sensor connector, or the mainframe harness.
- Intermittent fault not present at time of testing: possible causes include loose connections, corrosion, pushed-back pins, the controller itself, the wire harness, or a combination of these problems.
How to troubleshoot Bobcat M0909: first checks
- Check the actual fuel level in the tank first. If it is genuinely low, refuel before doing any further diagnosis.
- Inspect the fuel level sensor connector and the gateway controller connectors for moisture, corrosion, or pins that have been pushed back out of position.
- Check the mainframe wiring harness along wire 3100 or 3180 (depending on model) for chafing, loose connections, or damage.
- If the code is intermittent and not active during testing, recheck all connections in the circuit since the cause may not show up until the fault repeats.
- Confirm the key switch is in the run/enter position when testing, since that is a condition required for the code to be active.
How the code clears
The tank must be refilled to above a 1/4 tank of fuel to reset the fault condition. No separate reset procedure or scan tool clearing step is listed for this code beyond refueling above that level.
Affected models and serial ranges
M0909 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 M0909 mean?
It means the gateway controller has detected a low fuel level signal for 30 seconds while the key switch is on. It is most often a straightforward low-fuel warning, but it can also indicate a sensor or wiring fault.
How do I clear Bobcat M0909?
Refill the fuel tank to above 1/4 tank. That is the only clearing condition listed for this code; there is no separate reset procedure.
Can a bad fuel sensor cause M0909 even with a full tank?
Yes. A faulty fuel level sensor, or corrosion and pushed-back pins in the sensor or gateway controller connectors, can cause the controller to read a false low-fuel signal and set M0909 even if the tank isn't actually low.
Which Bobcat machines can show code M0909?
It applies across a range of skid-steer and compact track loader models including the S510, S530, S550, S570, S590, S630, S650, S750, S770 and the T550, T590, T630, T650, T750, T770, T870.
What wires are involved in the M0909 fuel level circuit?
The gateway controller supplies 12 volts to the fuel level sensor on wire 3100 or wire 3180, depending on the model, and monitors the return voltage on that same circuit.
Is M0909 dangerous to keep operating with?
It's not an immediate safety shutdown code, but ignoring it risks running the machine out of fuel unexpectedly, which can cause work interruptions and, in some fuel systems, air intrusion issues. Check the tank and wiring rather than ignoring the warning.
Why does M0909 stay on after I refuel a little?
The clearing condition requires the tank to be filled above 1/4 tank, not just any amount of fuel added. If you only add a small amount, the code may remain active until the level is back above that threshold.