Bobcat M2303 (23-03) Fault Code: Starter Relay Error Off
Also shown on the panel as 23-03
Starter Relay Error Off · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
M2303, shown as 23-03 on the panel, sets when the gateway controller commands a start but does not detect voltage for 3 seconds on the starter solenoid feedback wire (8250 or 3560). It means the controller sent the start signal on wire 8200 but never got confirmation back that the starter solenoid activated.
High severity. A no-start or intermittent no-start condition can leave the machine unusable in the field. It is not an immediate safety hazard by itself, but a starter circuit fault should be diagnosed before the next work shift since it can strand the machine or lead to further electrical damage if ignored.
What does Bobcat error code M2303 mean?
M2303 is a starter circuit feedback fault. When you turn the key switch to run/enter and give a start command, the gateway controller sends battery voltage out on wire 8200 to the starter relay and solenoid. The starter solenoid is supposed to send a confirmation signal back to the controller on wire 8250 or 3560 (depending on model wiring). If the controller does not see voltage on that feedback wire for 3 seconds after commanding a start, it logs M2303.
This is essentially a 'did the starter actually respond' check. The controller is not confirming its own output wire, it is confirming a separate feedback path, so the fault can point to a break anywhere in that loop: the relay, the solenoid, the wiring between them, or the controller itself.
The code is self resetting, meaning it will clear on its own once the feedback voltage is detected correctly on a later start attempt. It does not require a manual reset procedure, but the underlying wiring or component issue still needs to be found and fixed if the no-start or intermittent start problem continues.
What triggers a Bobcat M2303 code?
The gateway controller sets M2303 when, with the key switch (run/enter) on and a start command given, it does not detect voltage for 3 seconds on the starter solenoid feedback wire (8250 or 3560).
Common causes of M2303
- Open relay output wire 8200 or open starter solenoid feedback wire (8250 or 3560)
- Open supply wire 1030
- Open battery cable to the starter
- Faulty starter relay
- Faulty starter solenoid
- Faulty gateway controller
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, starter relay connectors, starter solenoid connections, engine harness, or 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 M2303: first checks
- Turn the key switch to run/enter and attempt a start while watching for the code, since it may only be present during an actual start command
- Inspect the starter relay and starter solenoid connectors for moisture, corrosion, or pushed-back pins
- Check wire 8200 (relay output to solenoid) and the feedback wire, 8250 or 3560, for continuity and open circuits
- Check supply wire 1030 for continuity
- Inspect the battery cable to the starter for a loose, corroded, or open connection
- Check the engine harness and mainframe harness connectors near the starter and gateway controller for corrosion or damage
- If the code will not repeat during testing, treat it as intermittent and focus on loose connections, corrosion, and connector pin condition rather than assuming a single failed part
How the code clears
M2303 is self resetting. No separate clearing step or manual reset procedure is listed. Once the controller detects proper feedback voltage on the starter solenoid feedback wire during a start attempt, the code clears on its own. The wiring or component problem that caused the fault should still be repaired even after the code clears, especially if the no-start condition was intermittent.
Affected models and serial ranges
M2303 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 M2303 mean?
It means the gateway controller commanded the starter to engage but did not detect voltage for 3 seconds on the starter solenoid feedback wire, 8250 or 3560, so it could not confirm the starter relay and solenoid responded.
What is the panel display number for M2303?
It shows on the panel as 23-03.
Will M2303 cause a no-start condition?
It can. Since the fault involves the starter relay feedback circuit, an open wire, bad relay, or bad solenoid tied to this code can prevent the starter from engaging at all.
Do I need to clear M2303 manually?
No. It is self resetting. There is no listed manual reset procedure, but you still need to repair the underlying wiring or component issue.
Why does M2303 come and go instead of staying on?
If the code is intermittent, the cause may be loose connections, corrosion, or pushed-back pins in the connectors rather than a fully failed part. These conditions can make contact and lose contact depending on vibration, moisture, or temperature.
Which wires are involved in the M2303 circuit?
Wire 8200 carries battery voltage from the starter relay to the starter solenoid. The feedback wire, either 8250 or 3560 depending on the model, sends confirmation back to the gateway controller. Supply wire 1030 also feeds the circuit.
Which Bobcat machines can show M2303?
It applies to S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, T770, and T870 models.