VFS A Pressure Output Failed Low
The engine's variable fuel system (VFS) pressure sensor is reporting a pressure reading that's too low, like a tire gauge stuck showing flat when the tire has air. The ECU can't get accurate fuel pressure feedback, which prevents proper fuel delivery adjustment.
The ECU monitors the variable fuel system pressure output signal from the fuel pressure sensor. It expects a voltage signal within a specific range that correlates to actual fuel pressure. When the signal voltage drops below the minimum threshold, the ECU interprets this as abnormally low pressure and triggers the fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Fuel Pressure Sensor Voltage | 0.5V to 4.5V (varies by application) | Below 0.3V sustained |
| Fuel Pressure (PSI equivalent) | 45-65 PSI depending on demand | Below 30 PSI or sensor reads below minimum |
Code P1915 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1915 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.