What is the cause of the P3073 fuel pump circuit electrical fault?
3 Answers
P3073 fuel pump circuit electrical fault is caused by an open/short circuit in the connection/wiring between the fuel pump and the fuel pump controller. Below is an introduction to the fuel pump: Introduction to the fuel pump: The fuel pump is a professional term in the automotive parts industry. It is one of the basic components of the fuel injection system in electronic fuel injection vehicles, located inside the vehicle's fuel tank. The fuel pump operates during startup and while the engine is running. If the engine stops but the ignition switch remains in the ON position, the HFM-SFI control module shuts off the power to the fuel pump to prevent accidental ignition. Function of the fuel pump: The fuel pump's function is to draw fuel from the fuel tank, pressurize it, and deliver it to the fuel supply line, working in conjunction with the fuel pressure regulator to establish a certain fuel pressure.
When the vehicle's OBD system reports a P3073 fault code, it usually indicates an electrical issue in the fuel pump circuit. I have encountered this situation multiple times, with common root causes including fuel pump motor burnout, short or open circuits in the wiring, blown fuses, relay failure, and control module abnormalities. Wiring aging and cracking or loose connectors are prone to occur in high-vibration areas; relay contact carbon buildup can cause unstable current; the fuel pump itself may fail due to long-term high-temperature wear. I recommend starting the inspection from the simplest steps: first, check if the corresponding fuse in the fuse box is blown and try replacing it; then test if the relay's clicking sound is normal; next, inspect wiring connectors for rust or corrosion; if the issue persists, it may be necessary to replace the fuel pump. Don't delay this issue, as interrupted fuel supply can cause engine stalling, posing high driving risks. Regular circuit maintenance can prevent problems before they occur.
After driving for a long time, I personally encountered the P3073 fault, which was caused by relay contact erosion. This code generally points to electrical issues in the fuel pump circuit, such as pump motor short circuits, open or shorted wiring, blown fuses, or relay failures. Worn or corroded wires and loose connectors are the most common causes; if the relay has poor contact, the current fluctuates erratically; an aging fuel pump can fail on its own. For diagnosis, a simple approach is: first, check the fuse for any signs of burning or blackening, then replace it to see if it works; next, listen for the relay's clicking sound; then unplug and clean the connector positions. If not addressed promptly, the car may break down on the road, costing time and money, so regular circuit maintenance is crucial to avoid unnecessary trouble.
