Bobcat M2503 (25-03) Fault Code: Traction Lock Pull Relay Error Off
Also shown on the panel as 25-03 · Also called Traction Pull Relay Error Off
Traction Lock Pull Relay Error Off · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Bobcat code M2503, panel code 25-03, means the gateway controller commanded the traction lock relay on but did not see the expected voltage on the feedback wire (3430 on some models, 4150 on others). When this code sets, the machine disables traction.
High severity. Traction is disabled the moment this code sets, so the machine cannot be driven until the fault is fixed. It is not an engine-damage emergency, but it stops work immediately and should be diagnosed before returning the machine to service.
What does Bobcat error code M2503 mean?
M2503 is set by the gateway controller when it commands the traction lock relay to close but does not detect voltage returning on the feedback wire, either wire 3430 or wire 4150 depending on the model. The traction lock relay and its solenoid control whether the drive system is allowed to engage, so this is a safety-related interlock circuit, not just a convenience feature.
Because the controller cannot confirm the relay actually switched, it disables traction rather than risk an uncommanded or unconfirmed drive engagement. This means the operator will lose the ability to drive the machine until the fault clears or is repaired.
This code applies across a wide range of 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/T870 lines. The exact feedback wire number and fuse involved can differ by model, but the failure logic is the same.
Common causes of M2503
- FRC1 fuse 9 or FRC1 fuse 6 open or blown, or fuse 9 open, depending on model
- Supply wire 1360 open, or ground wire 2025 or ground wire 2050/2060 open
- Feedback wire 3430 or feedback wire 4150 shorted to ground or open
- Traction lock solenoid wire 4100 shorted to ground
- Faulty traction lock relay
- Faulty traction lock solenoid
- Faulty gateway controller
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, traction lock relay connectors, or the mainframe harness
- Intermittent fault not present at time of testing, possibly caused by loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these
How to troubleshoot Bobcat M2503: first checks
- Confirm the conditions needed for the code to set are present: key switch in run/enter, engine running, PTOL enabled, and parking brake off. If any of these are not met, the code logic will not apply the same way.
- Check the relevant fuse for the model (FRC1 fuse 9, FRC1 fuse 6, or fuse 9) for continuity and proper seating in its holder.
- Inspect the traction lock relay and its connector for corrosion, moisture, or pushed-back pins, and reseat or clean as needed.
- Check supply wire 1360 and the applicable ground wire (2025 or 2050/2060) for continuity and secure connections.
- Trace feedback wire 3430 or 4150, depending on model, for shorts to ground or an open circuit between the relay and the gateway controller.
- Inspect traction lock solenoid wire 4100 for a short to ground.
- Check the gateway controller connectors and mainframe harness connectors for corrosion or pushed-back pins.
- If the code is intermittent and not present during testing, wiggle-test the harness and connectors while monitoring for the fault, since the cause may not be findable in a static check.
How the code clears
Once the repair is complete, the fix is confirmed by cycling power to the machine. No separate reset procedure or scan tool clearing step is listed beyond a power cycle.
Affected models and serial ranges
M2503 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 M2503 mean?
It means the gateway controller told the traction lock relay to turn on but did not see the expected voltage return on the feedback wire, so it disabled traction as a safety precaution.
What is the panel code number for M2503?
The numeric panel form is 25-03.
Can I still drive the machine with a M2503 code active?
No. Once this code sets, traction is disabled by the controller until the underlying fault is fixed.
Which Bobcat models can show M2503?
It appears on S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770/T870 models, though the specific fuse and feedback wire number involved can vary by model.
Why does my machine only show this code intermittently?
If the fault is not present when tested, the root cause may be a loose connection, corrosion, a pushed-back pin, a harness issue, or the controller itself. Intermittent faults like this can be hard to pin down without catching them while active.
How do I clear M2503 after repair?
Cycle power to the machine after completing the repair. No other clearing procedure is listed.
Is M2503 an electrical problem or a relay problem?
It can be either. The cause list includes blown fuses, open supply or ground wires, shorted or open feedback wires, a bad relay, a bad solenoid, or a gateway controller fault, so both wiring and hardware need to be checked.