CAT Engine 2916 Fault Code: Engine Cooling Fan Solenoid short to ground
Also called Engine Cooling Fan Solenoid - Current Above Normal, Engine Cooling Fan Solenoid : Current Above Normal, Engine Cooling Fan Solenoid Current Above Normal, Engine Cooling Fan Solenoid Short to Ground, Engine Cooling Fan Solenoid current above normal, Engine Cooling Fan Solenoid:Current Above Normal, Engine Cooling Fan Solinoid : Current Above Normal, Fan Drive Bypass Command Status : Current Above Normal
Engine Cooling Fan Solenoid short to ground · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
CAT fault code 2916 (SPN 4212 / FMI 6) means the ECM has detected a short circuit to ground, or current above normal, in the engine cooling fan control solenoid circuit. When this happens the ECM forces minimum current to the solenoid, which drives the fan pump to maximum pressure and pushes the cooling fan to maximum speed until the fault is fixed.
Medium severity. The engine itself is not damaged by this fault because the ECM's default response is to force the fan to maximum speed, which actually protects against overheating. The real issues are wasted fuel, excess noise, and the risk that a genuine wiring or solenoid failure gets ignored until it causes a bigger electrical problem. Diagnose it within the shift rather than running indefinitely with the fan pinned at maximum.
What does CAT Engine error code 2916 mean?
Code 2916 covers the engine cooling fan control solenoid circuit on C11, C13, C15, C18, C27, and C32 engines. The ECM manages fan speed by sending a variable current to this solenoid, which in turn controls a hydraulic pump that drives the fan motor. Lower current from the ECM means less oil bypass and a faster fan; higher current means more bypass and a slower fan.
This code sets when the ECM detects a short circuit to ground in the solenoid circuit, or in some descriptions, current above the normal expected range. Either way, the ECM cannot properly control solenoid current anymore.
As a safety default, the ECM sends minimum current to the solenoid whenever this fault is present. Minimum current means the pump bypasses less oil, so the fan pump defaults to maximum pressure and the fan runs at maximum speed until the fault clears. The code is logged in ECM memory and can be viewed on a display module or scan tool.
What triggers a CAT Engine 2916 code?
The ECM sets this code when it detects a short circuit to ground in the engine fan control solenoid circuit, or when solenoid current reads above the normal operating range. Normal solenoid current runs between 0.0 amperes (maximum fan rpm) and 1.4 amperes (minimum fan rpm) in one description, and between 0.1 amp and 1.8 amp in another, with the solenoid operating on a pulse width modulated signal between 15 VDC and 27 VDC (battery voltage). The ECM normally holds fan speed within ±50 rpm of the desired rpm using feedback from the engine cooling fan pump pressure sensor or the cooling fan speed sensor; when the short-to-ground condition is detected, that control loop is abandoned in favor of the minimum-current default.
Common causes of 2916
- Damaged, corroded, or loose connector, pin, or socket at the fan control solenoid or ECM connector, including connectors not fully coupled or inserted
- Chafed, pinched, or corroded wiring in the harness between the ECM and the fan control solenoid
- Short circuit between the harness connector for the fan control solenoid and the ECM (the specific fault condition for this code)
- Open circuit between the ECM and the connector for the engine fan control solenoid
- Faulty engine fan control solenoid that needs to be replaced
- Faulty ECM (least common cause; only pursue after wiring and solenoid are cleared)
How to troubleshoot CAT Engine 2916: first checks
- Visually inspect the connectors at the engine fan control solenoid and at the ECM. Confirm they are fully seated and coupled, and check for corrosion, moisture, or pushed-back pins.
- Trace the harness between the ECM and the solenoid looking for chafe points, pinch points, or abrasion damage where wire insulation could be worn through to bare metal or a ground path.
- Check the solenoid circuit for a short to ground using a multimeter with the harness disconnected from the ECM and the solenoid, rather than assuming the solenoid itself is bad.
- Use a diagnostic scan tool to view live solenoid current and confirm whether the ECM is holding minimum current as expected, and try the scan tool's fan override feature to manually cycle fan speed from minimum to maximum rpm.
- If wiring and connectors check out clean, test or swap the fan control solenoid before condemning the ECM.
How the code clears
No separate clearing step is listed beyond repairing the fault. Once the short to ground is repaired, corroded or damaged wiring is replaced, or the faulty solenoid is swapped, the ECM should stop forcing minimum current and resume normal PWM control of fan speed. Cycle the key or clear the code with a scan tool and verify the fan returns to modulating speed instead of running constantly at maximum.
Affected models and serial ranges
2916 appears in our records across 6 CAT Engine models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| C11 | Serial range not listed in source records |
| 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 2916 mean?
It means the ECM detected a short circuit to ground, or current above normal, in the engine cooling fan control solenoid circuit. As a safety default, the ECM sends minimum current to the solenoid, which pushes the cooling fan to maximum speed until the problem is fixed.
Is it safe to keep running the machine with code 2916 active?
Short term, yes, because the ECM's default response actually protects the engine by forcing maximum fan speed. But you will see reduced fuel economy and more fan noise, and running long-term without diagnosing it risks missing a wiring or solenoid failure that could worsen.
Why is my cooling fan stuck at full speed?
When the ECM detects this short-to-ground fault, it intentionally forces minimum current to the fan control solenoid, which results in maximum fan pump pressure and maximum fan speed. This is the ECM's fail-safe behavior, not a separate malfunction.
What is SPN 4212 / FMI 6?
SPN 4212 is the fan drive bypass command / fan control solenoid parameter, and FMI 6 indicates 'current above normal' or a short to ground condition. Together they correspond to CAT fault code 2916.
Can I use a scan tool to test the fan solenoid directly?
Yes. A diagnostic scan tool has a fan override feature that lets you manually command the fan from minimum to maximum rpm, which is useful for confirming whether the solenoid and wiring respond correctly once repairs are made.
What usually causes this fault?
Most cases trace back to damaged, corroded, or unseated connectors and wiring between the ECM and the fan control solenoid, or a short circuit to ground somewhere in that harness. A faulty solenoid is the next most common cause, with a faulty ECM being rare.
Does this code affect other engine systems?
Not directly. The fan control circuit is separate from fueling and emissions circuits, so this code by itself should not trigger derates. However, forcing maximum fan speed continuously will increase parasitic load on the engine and reduce fuel economy.