Water in Fuel Indicator
Indicates 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 detects water mixed with fuel, which can cause damage and engine performance issues.
What the computer is actually seeing
The ECM sees an input signal from the water sensor, typically a variable resistor that changes with water presence, sending a voltage signal usually between 0-5 volts.
What a healthy reading looks like
Voltage signal from the water sensor typically should be under 0.5 volts in clean fuel; above 0.5 volts indicates water presence.
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.
- 1Check fuel tank for signs of water contamination; look for sediment or water layer at the bottom.
- 2Inspect wiring and connectors related to the water sensor for damage or corrosion. Repair as needed.
- 3Test the voltage output of the water sensor; should be close to 0 volts if no water is present. Replace the sensor if reading is above 0.5 volts.
- 4If the sensor is fine, inspect the fuel supply for contamination; consider sampling and testing the fuel.
- 5Clear the code and run the engine; monitor the system for reoccurrence.
Common causes
- Faulty water detection sensor
- Contaminated fuel supply
- Poor sealing on fuel tank or fuel lines
- Damaged wiring or connectors to the water sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's better to address it soon as water in fuel can cause engine damage and performance issues.
Will this code come back after clearing?
If the water issue isn't resolved, yes, the code will likely reappear.
Why does this code sometimes appear with SPN 6130?
SPN 6130 indicates a specific fault in the water sensor, which can coincide with the water in fuel condition.
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 →