Second Fuel Pump Faulty or Ground Fault
Your vehicle has a second fuel pump that isn't working properly or has a bad electrical ground connection. Think of it like a backup water pump losing power—the fuel system can't maintain proper pressure when needed.
The ECM monitors voltage and current draw from the secondary fuel pump circuit during operation. It detects faults when pump voltage is too low, current draw is abnormal, or ground continuity fails. The system expects proper pump activation when the ignition turns on and during engine running conditions.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Fuel pump voltage | 10.5–14.5 volts | Below 8 volts or open circuit |
| Ground resistance | Less than 0.1 ohms | Greater than 5 ohms or infinite resistance |
Code P1248 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, P1248 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.