Fuel Temperature Sensor A Circuit High
What does P0183 mean?
The P0183 code means the vehicle's onboard diagnostic system has detected: Fuel Temperature Sensor A Circuit High. This is a low severity code.
Common Symptoms
- Check Engine Light on
- PCM reads fuel temperature as excessively low (e.g., -40 degrees F)
- Slightly incorrect fuel delivery
- Minor fuel economy decrease
- No major drivability concerns
Probable Causes (Ranked by Likelihood)
- Open circuit in the fuel temperature sensor or wiring Very High
- Failed fuel temperature sensor (open internally) High
- Disconnected or corroded sensor connector Moderate
- Broken wire in the sensor circuit Moderate
- PCM input circuit or reference voltage fault Low
Step-by-Step Diagnostic Procedure
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Read fuel temperature on a scan tool. A reading of -40 degrees F with the engine at operating temperature indicates a high circuit condition (open circuit pulling voltage high).
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Check the fuel temperature sensor connector -- it may be simply disconnected or have a pushed-out pin.
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Measure sensor resistance (should be 2,000-3,000 ohms at 68 degrees F). Infinite resistance means the sensor is open.
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Check the signal wire continuity from the sensor connector to the PCM. An open wire will pull the signal to 5V reference.
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Inspect the wiring for breaks, especially at connectors and routing points.
Frequently Asked Questions
Can I drive with code P0183?
Yes, you can drive normally. The PCM will use a default fuel temperature value. Fuel delivery will be slightly less precise but will not cause drivability problems.
Why does high circuit mean low temperature?
When the sensor circuit is open (broken wire or disconnected sensor), the signal voltage is pulled up toward the 5V reference. Since fuel temp sensors use NTC thermistors where high voltage equals low temperature, the PCM interprets this as -40 degrees F.
Is P0183 always a broken sensor?
Not always. Check the connector first -- a simple disconnected plug or corroded pin is a common cause. Also check for broken wires in the harness before replacing the sensor.