P0183 OBD2 Code Guide
P0183 is a powertrain diagnostic trouble code. Use this hub to understand the plain meaning, the first checks to run, and which vehicle-specific guides may be more useful before replacing parts.
Fuel Temperature Sensor 1 Circuit High Input
Code P0183 indicates that the Powertrain Control Module (PCM) has detected a voltage signal from Fuel Temperature Sensor 1 that is higher than the expected operating range. This 'high input' typically suggests an open circuit, a short to voltage, or a sensor reading an extremely low (or maximum) temperature, which is implausible under current operating conditions. The fuel temperature sensor provides crucial data to the PCM, allowing it to accurately calculate fuel density and adjust fuel injection timing and pulse width for optimal combustion, emissions, and fuel economy. When this data is inaccurate, the engine may experience poor fuel economy, rough idle, hard starting, or reduced performance.
Code verification standard
P0183 is published with SAE J2012 / ISO 15031-6 code structure plus OBD2 P0183 diagnostic context.
First checks
- - Read all stored and pending codes before clearing anything.
- - Save freeze-frame data so you know speed, load and temperature when the code set.
- - Inspect wiring, connectors, fuses, hoses and obvious leaks tied to the named system.
- - Compare live data against realistic values before buying sensors or modules.
- - Clear the code only after repair and complete a drive cycle to confirm it does not return.
P0183 diagnostic path
- 11. Visually inspect the Fuel Temperature Sensor 1 and its wiring harness. Look for any signs of damage, fraying, corrosion on the connector pins, or loose connections. Ensure the sensor is properly seated in its location (often in the fuel tank or fuel line).
- 22. Using an OBD-II scan tool, monitor the live data for Fuel Temperature Sensor 1. Compare its reading to the ambient air temperature (if the engine is cold) or a known good value. A P0183 often presents as an extremely low temperature reading (e.g., -40°F/-40°C) or a static, implausible high voltage reading.
- 33. Disconnect the sensor connector. With a multimeter, test the resistance of the fuel temperature sensor itself across its terminals. Compare this reading to manufacturer specifications for the current ambient temperature. An open circuit (infinite resistance) or a resistance value significantly out of range indicates a faulty sensor.
- 44. With the sensor disconnected, test the voltage at the sensor's harness connector. You should typically find a 5-volt reference signal and a good ground from the PCM. Check for continuity in the signal wire back to the PCM and test for any shorts to voltage or ground in the wiring harness. Repair any detected wiring issues.
- 55. If the sensor and wiring test perfectly within specifications, and all other related components are verified good, the issue might lie within the PCM itself. However, PCM failure is rare and should only be considered after thorough diagnosis of all other possibilities.
Verify before repair
- - Replace the faulty Fuel Temperature Sensor 1.
- - Repair or replace damaged, corroded, or shorted wiring and connectors leading to Fuel Temperature Sensor 1.
- - Clean any corrosion from the sensor's electrical connector terminals to ensure proper contact.
Vehicle-specific pages to check next
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