Water in Fuel Condition Detected
The P1140 code indicates that the water-in-fuel sensor has detected excessive water in the diesel fuel system. This typically occurs when water accumulates in the fuel filter/water separator, which can cause injector damage, poor combustion, and engine performance issues. The sensor triggers a warning light to alert the driver to drain the water separator immediately.
1. Symptoms You Will Notice
- Check Engine Light or Water-in-Fuel warning light on
- Engine hesitation, rough idle, or stalling
- Reduced fuel economy and power
- Difficulty starting the engine
2. Most Common Causes
- Faulty or internally worn accelerator pedal position (APP) sensor
- Loose, oxidized, or corroded electrical connections at the sensor connector
- Damaged wiring (cuts, chafing, or heat damage) in the harness between the pedal and ECM
- Intermittent ECM failure (less common)
- Resistance variations due to contamination or moisture in the connector
3. Step-by-Step Diagnosis
Step 1: Locate the fuel filter/water separator and drain any water using the drain valve.
Step 2: Inspect the water-in-fuel sensor wiring and connector for damage or corrosion.
Step 3: Test the sensor resistance with a multimeter; compare to manufacturer specs.
Step 4: If sensor is faulty, replace it and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, driving with water in the fuel can damage injectors and the fuel pump. Drain the water separator immediately.
How much does it cost to fix?▼
Typically $50-$150 for draining and sensor replacement if needed, but costs vary by shop.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.