FUEL TANK PRESSURE - EXCEEDS THRESHOLD
The fuel tank pressure is too high.
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What it means (plain English)
The fuel system has too much pressure in the tank, which can cause vapor leaks and affect fuel delivery.
What the computer is actually seeing
The ECM monitors fuel tank pressure via the fuel tank pressure sensor, which typically provides a voltage signal of 0.5 to 4.5 volts. If the sensor detects a pressure above normal operating values, usually over 5 inches of H2O (water column) or 9.0 kPa, this code is triggered.
What a healthy reading looks like
Normal tank pressure should be between 0 to 5 inches of H2O (0 to 9.0 kPa) under average conditions.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the fuel cap; is it sealed tight? If not, tighten or replace and retest.
- 22. Check for physical damage to the fuel filler neck. Look for cracks or holes that could cause pressure loss.
- 33. Inspect the wiring and connector to the fuel tank pressure sensor. Look for corrosion or broken wires.
- 44. Use a scan tool to check the fuel tank pressure sensor reading while the vehicle is running. Is it above normal (5 inches of H2O)? If yes, suspect a faulty sensor.
- 55. Check for issues in the EVAP system, including blockages in hoses or valves. Use a smoke test if necessary to identify leaks.
Common causes
- Faulty fuel tank pressure sensor
- Clogged EVAP system
- Damaged fuel filler neck
- Fuel cap not sealing properly
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive long distances as excess fuel pressure can affect performance and emissions.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code will likely reappear after driving the vehicle.
Why does this code show up with fuel cap issues?
A loose or damaged fuel cap can cause pressure changes in the tank, leading to this code being triggered.
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