Open or damaged signal wire between the fuel temperature sensor and the ECM; Corroded, loose, or disconnected electrical connector at the sensor; Failed fuel temperature sensor (internal open circuit or resistance drift); Short to voltage on the sensor signal circuit, often from chafed wiring near hot or moving components; Faulty ECM driver or internal pull-up resistor (less common but possible); Aftermarket or incorrect sensor installed that does not match the ECM calibration

DTC codes / P01xx · Fuel and air metering / P0183

P0183Fuel Temperature Sensor A Circuit High Input

Q: What does code P0183 mean?

Fuel Temperature Sensor A Circuit High Input. P0183 means the engine control module (ECM) has detected an abnormally high voltage on the signal circuit of fuel temperature sensor A, which is typically a thermistor whose resistance drops as fuel temperature rises. The high voltage tells the ECM that the sensor circuit is open, shorted to voltage, or that the sensor itself has failed in a way that mimics a cold fuel condition.

P0183 means the engine control module (ECM) has detected an abnormally high voltage on the signal circuit of fuel temperature sensor A, which is typically a thermistor whose resistance drops as fuel temperature rises. The high voltage tells the ECM that the sensor circuit is open, shorted to voltage, or that the sensor itself has failed in a way that mimics a cold fuel condition.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or hesitation when the engine is cold, because the ECM may use default fuel temperature values
Poor fuel economy or slightly increased emissions during warm-up
Hard starting or extended cranking in cold weather
In rare cases, a no-start condition if the ECM strategy relies heavily on fuel temperature for cold-start enrichment

Common causes, most likely first

Open or damaged signal wire between the fuel temperature sensor and the ECM
Corroded, loose, or disconnected electrical connector at the sensor
Failed fuel temperature sensor (internal open circuit or resistance drift)
Short to voltage on the sensor signal circuit, often from chafed wiring near hot or moving components
Faulty ECM driver or internal pull-up resistor (less common but possible)
Aftermarket or incorrect sensor installed that does not match the ECM calibration

How to diagnose and fix it

Connect a scan tool and record the fuel temperature sensor voltage and temperature readings with the key on and engine cold; compare to ambient temperature to confirm the fault is real.
Visually inspect the sensor connector and wiring for corrosion, loose pins, or obvious damage, and repair as needed.
Disconnect the sensor and measure resistance across its terminals; compare to the manufacturer's temperature-resistance chart to determine if the sensor is open or out of spec.
With the sensor disconnected, measure voltage on the signal circuit at the connector (key on) to check for a short to voltage or an open circuit; repair wiring if voltage is abnormal.
Perform a wiggle test on the harness while watching the scan tool fuel temperature reading to catch intermittent opens or shorts.
If wiring and sensor test good, check for continuity from the sensor connector to the ECM and verify the ECM is not setting the code due to an internal fault.
Replace the fuel temperature sensor only after electrical tests confirm it is faulty, then clear codes and verify the reading matches ambient temperature after a cold soak.

Fuel temperature sensor circuit checks that save time

A common mistake is replacing the fuel temperature sensor when the real problem is a chafed signal wire shorting to a nearby 12-volt source, which sets the same high-voltage code.
On many vehicles the fuel temperature sensor is integrated into the fuel rail pressure sensor or fuel composition sensor, so technicians replace the entire expensive assembly when only a separate thermistor has failed.
The ECM may substitute a default fuel temperature value when the sensor circuit is high, masking driveability symptoms and leading owners to ignore the code until an emissions test fails.
Intermittent P0183 codes often appear only after the engine bay heats up, because expansion opens a marginal connection inside a connector or a wire strands break inside intact insulation.
A fuel temperature sensor reading that stays fixed at minus 40 degrees or at a very high temperature with the key on is a classic sign of an open circuit, not a true temperature problem.

Can I keep driving with P0183?

The vehicle is generally safe to drive with P0183 because the ECM substitutes a default fuel temperature value, but you should avoid extended driving without diagnosis if you notice rough running, hard starting, or poor fuel economy. Have the circuit checked soon to prevent misdiagnosis of related fuel system codes and to ensure cold-start emissions stay within limits.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.