Fuel level sensor (sending unit) codes

How its codes differ

• P0463 (circuit high) means the signal is above the range the sender should produce. A worn resistor track, an open circuit or a poor terminal connection are the usual causes.
• Sulfur or fuel deposits on the sender contacts can cause erratic readings and P0463; Ford's bulletin for some 2004 to 2006 vehicles treats this with a fuel system cleaner and fresh fuel before replacing parts.
• A stuck float arm, a float that has filled with fuel and sunk, or a damaged tank can make the gauge read wrong without the electrical parts being at fault.

Codes

• P0463

  The fuel level sensor signal is higher than its normal range

  Severity: Monitor

Signs it's failing

• Fuel gauge stuck on empty or full, or swinging erratically
• Low fuel warning that does not match the fuel in the tank
• Check engine light with P0463
• Running out of fuel while the gauge shows fuel left

How to test it

1. Read stored codes with a scan tool and note what the fuel gauge shows compared with how much fuel you have actually added. (Low risk)

2. Measuring the sender resistance, testing the wiring and replacing the sender are jobs for a shop, because the sender is inside the tank. (Best left to a shop)

   Warning: Opening the fuel tank releases fuel and vapour that can catch fire from a spark or hot surface. Work like this needs a ventilated space, no ignition sources and proper fuel-handling equipment.

After the repair

• Check the gauge at several fuel levels over the next few fill-ups to confirm it reads correctly.
• Until the gauge is fixed, track fuel by distance driven since the last fill-up so you do not run out.
• Clear codes only after the repair and confirm P0463 does not return.