Bobcat M5406 (54-06) Fault Code: Tilt Spool Lock Short to Ground
Also shown on the panel as 54-06
Tilt Spool Lock Short to Ground · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
M5406 (panel code 54-06) sets when the Bobcat gateway controller commands voltage to the tilt spool lock solenoid but does not see it return on signal wire 4670/return wire 2670 (or on some models, signal wire 4370/return wire 2370). When this code is active, lift and tilt functions are disabled until it clears.
High severity. Lift and tilt are disabled while this code is active, which stops loader work entirely. It is not a code you can work around, but it does not by itself indicate a runaway safety event, so it is High rather than Critical.
What does Bobcat error code M5406 mean?
M5406 is an electrical fault tied to the tilt spool lock solenoid circuit. The gateway controller sends battery voltage to this solenoid whenever the seatbar is lowered into the operating position, which is the machine's way of confirming the operator is seated and ready before allowing hydraulic tilt function.
If the controller commands that voltage but does not detect it on the signal wire (4670) or return wire (2670), or on the equivalent 4370/2370 pair used on some models, it logs M5406. Because the circuit is being read as shorted to ground, the controller cannot verify the solenoid is working correctly, so it locks out both lift and tilt as a precaution.
This code will only set when the seatbar is down, since that is the only time the controller is actively powering this circuit. If you see the code while the seatbar is up, something else is going on and the seatbar position should be checked first.
What triggers a Bobcat M5406 code?
The code sets under key switch (run/enter) on conditions, when the seatbar is in the down position and the gateway controller does not detect the expected voltage on the tilt spool lock solenoid's signal or return wire.
Common causes of M5406
- Signal wire (4670 or 4370) or return wire (2670 or 2370) shorted to ground somewhere in the harness
- Failed or failing tilt spool lock solenoid
- Fault inside the gateway controller itself
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, the tilt spool lock solenoid connector, or the mainframe harness
- Loose connections or harness damage, especially if the code is intermittent and does not stay active during testing, in which case the cause may involve a combination of these problems rather than a single clean fault
How to troubleshoot Bobcat M5406: first checks
- Confirm the seatbar is fully down and the key switch is in run/enter before testing, since the circuit is only powered under these conditions
- Inspect the tilt spool lock solenoid connector and the gateway controller connectors for moisture, corrosion, or pins that have been pushed back out of place
- Visually trace the mainframe harness section carrying signal wire 4670/2670 (or 4370/2370 depending on model) for chafing, pinches, or exposed conductor that could touch ground
- Check for loose or corroded connections at every connector in this circuit, since intermittent versions of this code often trace back to a loose pin rather than a broken wire
- Test the tilt spool lock solenoid itself for a short to ground if the harness checks out clean
- If the code is not active during testing, treat it as intermittent and focus on connections, corrosion, and pushed-back pins rather than assuming the harness is fine
How the code clears
Cycle power to the machine after the repair is complete. No separate clearing step is listed beyond a power cycle.
Affected models and serial ranges
M5406 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 M5406 mean?
It means the gateway controller commanded voltage to the tilt spool lock solenoid while the seatbar was down, but did not detect that voltage on the signal or return wire, indicating a short to ground in that circuit.
Why are lift and tilt disabled when M5406 is active?
The controller cannot confirm the tilt spool lock solenoid circuit is working correctly, so it disables both lift and tilt as a safety precaution until the fault is resolved.
Which wires are involved in M5406?
Depending on the model, the circuit uses signal wire 4670 and return wire 2670, or on other models signal wire 4370 and return wire 2370. Both pairs serve the same tilt spool lock solenoid function.
Why does M5406 only show up when the seatbar is down?
The gateway controller only supplies battery voltage to the tilt spool lock solenoid when the seatbar is in the down position, so the fault condition can only be detected while that circuit is powered.
What if the code does not stay on during testing?
An intermittent M5406 can still point to loose connections, corrosion, pushed-back pins, the controller, or the wire harness. If it is not active when you test, the exact cause may not be pinpointed right away.
How do you clear M5406 after a repair?
Cycle power to the machine. No additional reset procedure is listed.
Which Bobcat machines can show code M5406?
It applies across the S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770/T870 model lines.