P0183 — Fuel Temperature Sensor “A” Circuit High #

DTC P0183 means the engine control module has detected an abnormally high electrical signal from the Fuel Temperature Sensor “A” circuit.

The important distinction is that “Circuit High” refers to the electrical signal, not to fuel that is physically too hot.

On many analog fuel-temperature sensor circuits, a high signal voltage can correspond to an implausibly low calculated fuel temperature and may be caused by an open circuit, poor connector contact, high resistance, damaged wiring or a faulty sensor.

The exact circuit design and diagnostic threshold vary by manufacturer and engine, so vehicle-specific wiring diagrams and specifications should always be used.

What Does P0183 Mean? #

The fuel temperature sensor provides the ECM or PCM with information about fuel temperature.

Depending on the vehicle, the sensor may be:

• a separate fuel temperature sensor;
• integrated into another fuel-system sensor;
• part of a fuel composition or fuel-condition sensor;
• installed in the fuel supply system, fuel rail or another manufacturer-specific location.

The control module monitors the sensor signal and checks whether it remains within an expected electrical range.

If the signal voltage becomes too high for the calibrated period of time, P0183 may be stored.

Does P0183 Mean the Fuel Is Too Hot? #

No.

P0183 describes a high electrical input from the sensor circuit.

On many temperature-sensor circuits, the sensor is a thermistor whose resistance changes with temperature. The control module uses that resistance to determine the signal voltage and calculate temperature.

On common negative-temperature-coefficient designs, an open circuit or very high resistance can cause the signal voltage to rise toward the reference voltage. The ECM may then interpret the signal as an extremely cold temperature.

For example, some manufacturer diagnostic strategies associate a fuel-temperature signal near the upper end of the sensor voltage range with a calculated temperature around −40 °C.

The exact voltage and temperature values must not be assumed for every vehicle.

Common Symptoms of P0183 #

Many vehicles may show no obvious drivability symptom other than the check-engine light.

Possible symptoms include:

• check-engine light illuminated;
• fuel-temperature live data showing an implausibly low value;
• fuel-temperature reading fixed at one extreme;
• related fuel-temperature sensor codes;
• hard starting on some applications;
• changes in fuel-management strategy on some engines;
• in some cases, no noticeable engine-performance problem.

Do not assume that hard starting, poor economy or stalling must occur simply because P0183 is stored.

Most Likely Causes of P0183 #

Possible causes include:

• disconnected fuel temperature sensor;
• open signal circuit;
• open sensor ground or low-reference circuit;
• high resistance in a connector or terminal;
• corroded sensor connector;
• damaged wiring;
• signal wire shorted to reference voltage or another voltage source;
• internally faulty fuel temperature sensor;
• poor terminal tension at the sensor or ECM connector;
• shared reference-voltage circuit fault;
• incorrect previous wiring repair;
• less commonly, an internal ECM/PCM fault.

How to Diagnose P0183 #

1. Record All Codes and Freeze-Frame Data #

Before clearing anything, record:

• P0183;
• all other fuel-temperature DTCs;
• reference-voltage or sensor-supply codes;
• fuel-system codes;
• freeze-frame data;
• fuel temperature shown by the scan tool.

Related codes can help distinguish a circuit fault from a plausibility or intermittent signal problem.

2. Look at Fuel Temperature Live Data #

One of the fastest diagnostic clues is the fuel-temperature PID.

With the vehicle cold after sitting for several hours, compare the reported fuel temperature with other reasonable temperature references such as:

• ambient temperature;
• intake-air temperature;
• engine-coolant temperature before startup.

The values do not have to be identical, but a fuel-temperature reading showing an extreme value that is physically impossible is a strong clue.

If the scan tool displays approximately −40 °C or another very low limit value on an analog system, investigate an open circuit or high signal voltage.

3. Identify the Sensor and Circuit Design #

Do not begin electrical testing until you know exactly which component the manufacturer calls Fuel Temperature Sensor “A”.

Use the wiring diagram to identify:

• sensor location;
• number of wires;
• reference-voltage circuit;
• signal circuit;
• sensor ground or low-reference circuit;
• whether the sensor is integrated into another component.

This prevents confusion with fuel-pressure, intake-air-temperature or other nearby sensors.

4. Inspect the Connector and Harness #

Inspect the sensor connector and wiring carefully.

Look for:

• disconnected connector;
• corrosion;
• water or fuel contamination;
• bent terminals;
• backed-out terminals;
• poor pin tension;
• broken wires near the connector;
• harness chafing;
• heat damage;
• previous splice repairs.

An open connector can produce exactly the type of high-voltage signal that sets P0183 on many systems.

5. Check Reference Voltage and Ground #

Using the correct wiring diagram and manufacturer procedure, verify the sensor’s electrical supply and ground.

Depending on the design, the circuit may use a regulated reference voltage provided by the ECM.

If the reference voltage is incorrect, check whether other sensors sharing that reference circuit are also affected.

A fault elsewhere on a shared reference circuit can sometimes influence several sensor readings at once.

6. Check the Signal Circuit #

If the signal remains too high, check the signal wire for:

• open circuit;
• high resistance;
• short to reference voltage;
• short to battery voltage;
• poor connector contact.

Compare voltage measurements with the manufacturer specification rather than using a universal threshold.

7. Compare Sensor Response With Temperature #

If the sensor is a conventional thermistor and the manufacturer provides a resistance-versus-temperature chart, test the sensor according to that chart.

The resistance should change predictably as temperature changes.

Do not use a generic resistance specification from another vehicle. Sensor calibration varies.

8. Use Connector Testing to Separate Sensor and Wiring Faults #

On some systems, manufacturer service information provides a test using a known resistance, jumper or scan-tool observation to determine whether the wiring and ECM can respond correctly when the sensor is disconnected.

Follow the exact OEM procedure.

Do not randomly short sensor terminals together because doing so can damage a reference-voltage circuit or create additional faults.

9. Perform a Wiggle Test #

If P0183 is intermittent, monitor the fuel-temperature PID while gently moving the harness and connector.

A sudden jump to an extreme temperature or abrupt voltage change can reveal:

• broken conductor;
• poor terminal contact;
• connector damage;
• intermittent open circuit.

10. Consider the ECM Only After the Circuit Is Verified #

Internal ECM or PCM failure is possible but should normally be considered only after:

• the sensor has been tested;
• reference voltage is correct;
• ground is correct;
• signal wiring has been checked;
• connector terminals have been inspected;
• vehicle-specific diagnostic tests point toward the controller.

P0183 vs P0182 #

P0183 indicates that the Fuel Temperature Sensor “A” circuit signal is too high.

P0182 — Fuel Temperature Sensor “A” Circuit Low indicates the opposite electrical condition: the signal is below the expected range.

On many analog thermistor circuits:

• high signal voltage can correspond to an extremely cold calculated temperature;
• low signal voltage can correspond to an extremely hot calculated temperature.

Exact behavior depends on the circuit design.

P0183 vs P0181 #

P0181 is generally a range/performance or plausibility fault.

The electrical signal may still remain within the normal voltage range, but the calculated fuel temperature does not behave as expected compared with other temperatures or operating conditions.

P0183 is more directly associated with the signal reaching the high electrical limit.

P0183 vs P0184 #

P0184 indicates an intermittent fuel-temperature sensor circuit problem.

If P0184 and P0183 occur together, inspect the connector and harness especially carefully for intermittent open circuits, loose terminals or vibration-related wiring faults.

P0183 vs P0180 #

P0180 is a more general Fuel Temperature Sensor “A” circuit fault.

The manufacturer may use P0180 when the circuit fails a broader diagnostic test, whereas P0183 specifically identifies the high-signal condition.

Can an Open Circuit Cause P0183? #

Yes, on many analog temperature-sensor circuits.

If the signal wire or sensor circuit becomes open, the control module’s internal pull-up can cause the signal voltage to rise toward the reference voltage.

The ECM then sees a high input and can store P0183.

This is why a disconnected sensor can produce the same DTC as some sensor failures.

Can a Bad Fuel Temperature Sensor Cause P0183? #

Yes.

If the sensor develops excessive internal resistance or becomes electrically open, it can produce a high signal voltage.

However, wiring and connector faults can produce the same result, so the sensor should not be replaced until the circuit has been checked.

Can P0183 Be Caused by a 5V Reference Problem? #

Potentially.

If the fuel temperature sensor uses a regulated reference-voltage circuit, a fault affecting that reference may influence the sensor signal.

Check whether other sensors sharing the same reference supply also show abnormal readings or related DTCs.

Can You Drive With P0183? #

In many cases the vehicle may continue to run normally because the ECM can substitute a default value when the sensor signal is implausible.

However, the fuel-temperature information may be used for fuel-management or diagnostic calculations, so the fault should still be repaired.

If P0183 occurs with hard starting, severe drivability problems, fuel-pressure faults or other electrical codes, diagnose those symptoms before continued driving.

Common Repairs for P0183 #

The correct repair depends on the test results. Possible repairs include:

• reconnecting a disconnected sensor;
• repairing an open signal wire;
• repairing damaged sensor ground wiring;
• repairing a short to voltage;
• cleaning or repairing corroded terminals;
• repairing damaged harness sections;
• replacing a confirmed faulty fuel temperature sensor;
• repairing a shared reference-voltage circuit;
• repairing an ECM connector problem;
• rarely, replacing or repairing the ECM/PCM when manufacturer testing confirms an internal fault.

Common P0183 Diagnostic Mistakes #

• Assuming “Circuit High” means hot fuel. It refers to high electrical signal voltage.
• Replacing the sensor without checking the connector. A disconnected or open circuit can create the same symptom.
• Using a generic resistance value. Sensor calibration varies by vehicle.
• Ignoring live data. An extreme fuel-temperature PID can quickly reveal the nature of the fault.
• Confusing the fuel temperature sensor with another sensor. Confirm its location and wiring first.
• Replacing the PCM too early. Wiring and connector problems are much more appropriate to rule out first.
• Assuming P0183 must cause drivability symptoms. Some vehicles may show only the warning light.

Related OBD2 Codes #

• P0180 — Fuel Temperature Sensor “A” Circuit
• P0181 — Fuel Temperature Sensor “A” Circuit Range/Performance
• P0182 — Fuel Temperature Sensor “A” Circuit Low
• P0184 — Fuel Temperature Sensor “A” Circuit Intermittent

Browse the Powertrain OBD2 Codes section for additional fuel-system and sensor diagnostic trouble codes.

P0183 FAQ #

What should I check first for P0183? #

Check the fuel-temperature live data, then inspect the sensor connector and wiring. An implausibly low temperature reading can be a strong clue that the signal circuit is open or electrically high.

Does P0183 mean the fuel is overheating? #

No. P0183 means the sensor circuit signal is electrically high. On many systems, a high signal actually corresponds to a very low calculated fuel temperature.

Can unplugging the sensor set P0183? #

Yes, on many analog sensor circuits. Disconnecting the sensor can leave the signal pulled toward the reference voltage and cause a high-input DTC.

Should I replace the fuel temperature sensor? #

Only after confirming that the wiring, reference voltage, ground and connector are correct and that the sensor itself does not meet the manufacturer specification.

Can P0183 clear itself? #

If the electrical fault disappears, the warning lamp may eventually switch off after the required fault-free operating cycles, but the diagnostic history can remain stored. Repair intermittent wiring problems rather than relying on the code to disappear.