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 engine control module (ECM) has detected water in the fuel. This can damage the engine or injectors if not addressed.
What the computer is actually seeing
The ECM reads the fuel water level sensor, which fluctuates between 0V (no water) and around 5V (high water content).
What a healthy reading looks like
0V to 1V indicates no water; 4V to 5V indicates high 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.
- 11. Check the fuel water separator for water accumulation, drain if necessary. Is water present?
- 22. Inspect wiring and connectors to the fuel water separator sensor for damage or corrosion. Are they intact?
- 33. Test the fuel water separator sensor with a multimeter. Should read between 0-1V with no water. What is the reading?
- 44. If voltage is abnormal, replace the fuel water separator sensor. Did the code clear?
- 55. If the problem persists, check the ECM for faults and consult diagnostic manual.
Common causes
- Faulty fuel water separator sensor
- Water in fuel tank
- Wiring issues to the sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to not drive, as water can damage the fuel system and engine.
Will this code come back after clearing?
If the water issue is not resolved, it will likely come back.
Why does this code appear with SPN 1002?
SPN 1002 is related to fuel pressure; both codes often indicate fuel system issues.
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