Bobcat M0522 (05-22) Fault Code: Hydraulic Charge Pressure Out of Range Low
Also shown on the panel as 05-22
Hydraulic Charge Pressure Out of Range Low · ai-assisted, editor-reviewed · Last updated 2026-07-12
TL;DR
Bobcat fault code M0522 (also shown on the panel as 05-22) means the main controller lost the signal from the hydraulic charge pressure sensor. It sets when the controller reads no voltage on that sensor's signal wire for 30 seconds. Most of the time this is a wiring or connector fault or a failed sensor, not a real drop in hydraulic pressure. The usual cause is a shorted or open signal wire, a bad 8.0-volt supply wire, a corroded connector, or a failing charge pressure sensor.
Medium severity. Often a sensor or wiring signal fault rather than a true pressure loss. But if the machine also drives weakly or not at all, treat it as a possible real low-charge-pressure condition and stop.
What does Bobcat error code M0522 mean?
M0522 is a hydraulic charge pressure sensor code on Bobcat S-series and T-series loaders. It is an M-series code from the machine's main (Gateway) controller, also shown on the panel as 05-22. The charge pressure sensor runs on an 8.0-volt supply from the controller and reports pressure back on a signal wire. The controller sets M0522 when it reads no voltage on that signal wire for 30 seconds, which means the signal has been lost rather than reading high or low.
Because the code is about a missing signal, it usually points to the sensor, its connector, or the wiring, not necessarily to an actual loss of hydraulic charge pressure. That distinction matters: charge pressure feeds the hydrostatic drive system, so if the machine also drives poorly you should treat it as a possible real pressure problem, check the hydraulic oil, and confirm with a gauge before running.
What triggers a Bobcat M0522 code?
The controller sets M0522 when the key switch is on (run/enter) and it detects no voltage for 30 seconds continuous on the hydraulic charge pressure sensor signal wire. The signal wire is 3190 or 3420 depending on the machine. Because the trigger is a total loss of signal, an open or a short to ground on that circuit is the most common reason the code appears.
Common causes of M0522
- Signal wire (3190 or 3420, depending on the machine) shorted to ground or open.
- 8-volt supply wire (5190 or 3400, depending on the machine) shorted to ground or open.
- A failed hydraulic charge pressure sensor.
- Moisture, corrosion, or pushed-back pins in the sensor connector at the main hydraulic filter, the controller connectors, or the mainframe harness.
- A weak or failing hydraulic charge pump, or low or contaminated hydraulic oil, producing a genuinely low charge pressure rather than a lost signal.
- A faulty main (Gateway) controller (rare, checked only after the sensor and wiring test good).
How to troubleshoot Bobcat M0522: first checks
- Check the hydraulic oil level and condition first. Low or contaminated oil can cause genuinely low charge pressure, and it is the cheapest thing to rule out.
- Note what the code reports: a lost sensor signal, not a confirmed low pressure. Watch whether the machine also drives or lifts weakly, which would point to a real pressure problem.
- The charge pressure sensor sits at the main hydraulic filter. Inspect that connector for moisture, corrosion, or pushed-back pins, the most common cause of a lost signal.
- Check the signal wire (3190 or 3420) from the sensor to the controller for a short to ground or an open.
- Check the 8-volt supply wire (5190 or 3400) for a short to ground or an open. The sensor cannot report without its 8.0-volt supply.
- If the connector and wiring test good, replace the charge pressure sensor. If the machine also drives weakly, have actual charge pressure measured with a gauge, since a weak charge pump can be the real cause.
How the code clears
M0522 is self-resetting. Once the controller reads a valid signal again, the code clears on its own without a scan tool. If it clears and returns, the wiring, connector, or sensor fault is still present.
Affected models and serial ranges
M0522 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 triggers a Bobcat M0522 code?
The main controller sets M0522 when it detects no voltage for 30 seconds on the hydraulic charge pressure sensor signal wire. The sensor runs on an 8.0-volt supply from the controller, so a lost signal points to the sensor or its wiring.
What is code 05-22 on a Bobcat?
05-22 is the two-part panel form of the same code as M0522: Hydraulic Charge Pressure Out of Range Low. Bobcat shows the fault both ways, so 05-22 and M0522 mean the same thing.
Is my Bobcat's hydraulic pressure actually low with an M0522?
Not always. The code sets on a lost sensor signal, which is usually wiring or a failed sensor. If the machine still drives and lifts normally it is likely electrical; if it drives weakly, check the hydraulic oil and confirm charge pressure with a gauge, since a weak charge pump can be the real cause.
Does M0522 clear on its own?
Yes. It is self-resetting: once the controller reads a valid sensor signal again, the code clears without a scan tool. If it clears and comes back, the wiring, connector, or sensor fault is still present.