CAT Engine 2673 Fault Code: Remote Shutdown Input : Voltage Above Normal
Also called Remote Shutdown Input - Voltage Above Normal, Remote Shutdown Input open/short to +batt, Remote Shutdown Input voltage above normal, Remote Shutdown Input:Voltage Above Normal, Remote Shutdown Switch Voltage Above Normal
Remote Shutdown Input : Voltage Above Normal · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT code 2673 (SPN 4215 / FMI 3) means the ECM sees both contacts of the ground level shutdown switch in the open state, a condition read as voltage above normal on that circuit. The engine keeps running if it's already running, but it will not start again until the switch is back in RUN (or STOP position is cleared) and, on some setups, ECM power is cycled. This affects C13, C15, C18, C27, and C32 engines.
Medium severity. The engine does not lose power or shut down immediately when this code sets, and there are no performance effects noted. But the fault blocks restarting until the switch and wiring are checked, which can strand a machine, so it should be diagnosed the same shift it appears.
What does CAT Engine error code 2673 mean?
Code 2673 is set by the ECM when it detects a voltage above normal on the ground level shutdown circuit. In plain terms, both switch contacts on the ground level (remote) shutdown switch are reading open at the same time, which the ECM interprets as an abnormal voltage condition rather than a valid RUN or STOP signal.
The ground level shutdown switch lets someone stop the engine from outside the cab, useful during service work or in an emergency. Lifting the red guard and toggling the switch to SHUTDOWN (or STOP) tells the ECM to disable fuel injection. The status screen will show "INJECTION DISABLED" and "REMOTE SHUTDOWN" when this happens.
Importantly, the ECM itself stays powered even when the engine is shut down this way. A scan tool can still talk to the ECM. If the switch's two contacts change to the same state while the engine is already running, the engine keeps running and the code is simply logged for later review. But the ECM will refuse to allow a restart until the shutdown switch is confirmed back in the RUN position, and engine rpm reads zero before it will crank.
Common causes of 2673
- Connectors, pins, or sockets at the ECM or shutdown switch are not fully coupled or seated
- Corrosion, abrasion, or pinch points in the wiring harness between the ECM and the ground level shutdown switch
- The ground level shutdown switch itself is not operating normally and needs to be tested or replaced
- A general problem in the harness and/or a problem with the ECM
- An intermittent wiring or connection fault that only shows up under vibration or temperature change
- A fault with the ECM itself, though this is listed as a possible cause only after wiring and switch are ruled out
How to troubleshoot CAT Engine 2673: first checks
- Visually inspect the ground level shutdown switch and its red cover guard, and confirm the switch is fully in the RUN position, not stuck partway or damaged
- Check all connectors and pins at the ECM and at the shutdown switch for full seating, corrosion, or bent pins
- Trace the harness between the ECM connector and the shutdown switch looking for chafe points, pinches, or abrasion damage, especially anywhere the harness crosses moving parts or sharp edges
- Wiggle-test the harness and connectors while watching for the code to change state, since an intermittent short or open can be hard to catch otherwise
- Pull the code with a diagnostic scan tool to confirm current versus logged status, and check the status screen for "INJECTION DISABLED" and "REMOTE SHUTDOWN" messages
- If wiring and switch check out, consider the ECM itself as a possible cause, but only after eliminating the harness and switch
How the code clears
No separate clearing step is listed beyond returning the ground level shutdown switch to the RUN position. On some versions, engine rpm must read zero and, in other cases, the electrical power to the ECM must be cycled before the ECM will allow the engine to restart. Once wiring or switch repairs are made, verify the code no longer sets active before returning the machine to service.
Affected models and serial ranges
2673 appears in our records across 5 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C13 | Serial range not listed in source records |
| C15 | Serial range not listed in source records |
| C18 | Serial range not listed in source records |
| C27 | Serial range not listed in source records |
| C32 | Serial range not listed in source records |
Frequently asked questions
What does CAT code 2673 mean?
It means the ECM detected voltage above normal on the ground level shutdown circuit because both contacts of the remote/ground level shutdown switch read open at the same time. It's a wiring or switch fault code, not a sign of engine damage.
Will the engine shut down when code 2673 sets?
Not on its own. If the engine is already running when both switch contacts change to the same open state, the engine keeps running and the code is simply logged. There are no performance effects noted for this fault.
Why won't the engine restart after this code appears?
The ECM requires the ground level shutdown switch to be back in the RUN position, and in some cases engine rpm at zero or ECM power cycled, before it will allow a restart. If the switch or wiring is faulty, the ECM may never see a valid RUN signal.
What are the most common causes of code 2673?
Loose or unseated connectors, corrosion or abrasion damage in the harness between the ECM and the shutdown switch, a failed or intermittent shutdown switch, and less commonly a problem with the ECM itself.
Can I still use a diagnostic scan tool if the engine is shut down by this switch?
Yes. The ECM stays powered even when the ground level shutdown switch has disabled fuel injection, so a scan tool can still communicate with it to read codes and status.
Is code 2673 the same as a normal remote shutdown activation?
No. A normal shutdown happens when the switch is deliberately toggled to STOP or SHUTDOWN. Code 2673 sets when the ECM sees an abnormal open state on both switch contacts, which points to a wiring or switch problem rather than an intentional shutdown.
Which CAT engines can show code 2673?
It applies to C13, C15, C18, C27, and C32 engines equipped with a ground level or remote shutdown switch circuit.