Water in Fuel Indicator
Indicates the presence of water 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 system has detected water mixed with the fuel, which can cause performance issues and potential engine damage.
What the computer is actually seeing
The engine control module (ECM) monitors the fuel system for moisture levels. When water is detected above safe thresholds, it triggers this fault code.
What a healthy reading looks like
Water content should be less than 200 ppm; ECM alerts at 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. Check the fuel quality. Examine the fuel for water contamination visually and consider using a water detection paste. If contaminated, proceed to step 2. Decision: Is fuel clean? Yes: Continue; No: Replace fuel and clean the system.
- 22. Inspect the fuel filter and water separator. Drain any accumulated water. Decision: Is there significant water accumulation? Yes: Replace the filter; No: Continue.
- 33. Test the fuel/water separator sensor. Measure sensor output voltage. Expected voltage is within 0.5V-4.5V when dry. Decision: Is reading within range? Yes: Check wiring; No: Replace the sensor.
Common causes
- Water contamination from fuel supply
- Faulty fuel/water separator sensor
- Damaged fuel lines or filters allowing water entry
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
It's best to resolve this soon; driving with water in fuel can lead to engine damage.
Will this code come back after clearing?
It can return if the source of water contamination isn't fixed, so thorough inspection is key.
Why does this code show up with other codes?
It may indicate a systemic issue with fuel quality that affects multiple engine sensors.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →