Bobcat L7404 (74-04) Fault Code: Gateway Controller No Communication
Also shown on the panel as 74-04 · Also called Main Controller No Communication
Gateway Controller No Communication · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
L7404 (panel form 74-04) means the left hand panel has lost CAN communication with the gateway controller. If the fault stays active for 30 seconds, the machine will shut down. It clears itself once communication is restored, but the underlying wiring or connector issue needs to be found and fixed.
High severity. L7404 will shut the machine down if it stays active for 30 seconds, so it is not something to keep operating through. Treat it as a stop-soon fault: get the machine to a safe spot before diagnosing further, since a shutdown can happen without warning while driving or lifting.
What does Bobcat error code L7404 mean?
L7404 sets when the left hand panel cannot talk to the gateway controller over the CAN bus. The gateway controller acts as a communication hub between machine systems, and the left hand panel relies on it to send and receive operating data. When that link drops, the machine's controllers cannot trust the information coming from the panel, which is why Bobcat has it force a shutdown rather than let the machine run blind.
CAN communication uses two wires: CAN high and CAN low. On these machines, wire numbers starting with 91xx and 95xx are CAN high, and wire numbers starting with 92xx and 96xx are CAN low. A problem on either of these wire pairs, or in any connector along that circuit, can break the communication link and set the code.
If the code is active for 30 seconds, the machine will shut down. This is a built-in protection response, not a separate malfunction, so a shutdown after a sustained L7404 is expected behavior rather than a second fault to chase.
Common causes of L7404
- CAN communication wires 91xx/95xx (CAN high) or 92xx/96xx (CAN low) shorted to supply voltage, shorted to ground, or open
- A fault in the left hand panel itself
- Moisture, corrosion, or pushed back pins in the gateway controller connectors, auxiliary controller connectors, ACS controller connectors, drive/drive plus connectors, left hand panel connector, ACS harness, AWS/SJC harness, cab harness, or mainframe harness
- An intermittent condition that is not present at the time of testing, which can involve loose connections, corrosion, pushed back pins, the controller, the wire harness, or a combination of these issues
How to troubleshoot Bobcat L7404: first checks
- Turn the key switch to run/enter and confirm whether L7404 is active now or was only stored as a history code, since an intermittent code may not be present during testing
- Inspect the left hand panel connector and the gateway controller connector for moisture, corrosion, or pins that have pushed back out of their sockets
- Check the CAN high wires (91xx/95xx) and CAN low wires (92xx/96xx) for signs of chafing, pinching, or exposed conductor that could short to ground or to supply voltage
- Inspect connectors on the auxiliary controller, ACS controller, and drive/drive plus systems, along with the ACS harness, AWS/SJC harness, cab harness, and mainframe harness, since any of these can interrupt the CAN circuit
- Wiggle-test harness connectors and wiring while watching for the code to trigger, which can help catch an intermittent connection problem that is not present at rest
How the code clears
L7404 is self resetting. There is no separate manual clearing procedure listed. Once the CAN communication fault between the left hand panel and gateway controller is repaired and communication is restored, the code clears on its own.
Affected models and serial ranges
L7404 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 |
| S650 | SN A3NV11001-13098, SN A3NV13099-99999, SN A3NW11001-11248, SN A3NW11249-99999 |
| S750 | SN A3P211001-299999 |
| S770 | SN A39511001-99999, 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 L7404 mean?
It means the left hand panel has lost CAN communication with the gateway controller. The panel and controller talk over a CAN high and CAN low wire pair, and when that link fails the code sets.
Will L7404 shut my machine down?
Yes, if the code stays active for 30 seconds the machine will shut down. This is intentional protection behavior since the machine cannot rely on panel data without communication.
Do I need to manually clear code L7404?
No separate clearing step is listed. The code is self resetting once the communication fault is repaired.
What is the difference between L7404 and the panel code 74-04?
They are the same fault. L7404 is the alphanumeric code and 74-04 is its numeric panel display form.
What wires should I check first for L7404?
Check the CAN high wires, numbered 91xx and 95xx, and the CAN low wires, numbered 92xx and 96xx, for shorts to ground, shorts to supply voltage, or open circuits.
Why does my L7404 code come and go?
An intermittent L7404 usually points to a loose connection, corrosion, or a pushed back pin somewhere in the affected connectors or harnesses. These conditions can clear on their own when the machine vibrates or the connector shifts, which is why the fault may not be present when you test it.
Which Bobcat models can get an L7404 code?
This code applies to S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, T770, and T870 models.