Water in Fuel Indicator
Indicates that water has been detected in the fuel system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer sees too much water in the fuel, which can cause engine problems.
What the computer is actually seeing
The engine control module (ECM) monitors water content in fuel through a dedicated sensor. When water levels exceed the threshold, usually around 0.05% of total fuel volume, the code triggers an alert.
What a healthy reading looks like
Water levels should be below 0.05% (500 ppm).
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 tank for signs of water contamination (look for separation in the fuel).
- 22. Check the fuel filter for water; drain it if necessary.
- 33. Verify the functionality of the water-in-fuel sensor (provide it with known good voltage).
- 44. Check the wiring and connectors at the sensor for signs of damage or corrosion. If the wiring is damaged, repair/replace as needed.
- 55. If all checks are normal but the code persists, consider replacing the water-in-fuel sensor.
Common causes
- Water contamination in fuel tank
- Faulty water-in-fuel sensor
- Poor fuel quality
- Damaged fuel lines or filter
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Driving with water in the fuel can cause engine damage, so it's best to address it soon.
Will the code come back after fixing?
If the underlying issue of water contamination isn't resolved, the code will likely return.
Why does this code often pair with other SPNs?
It's common for water issues to affect other related systems, which may trigger additional codes.
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