Fuel and air

P0183 — Fuel Temperature Sensor A Circuit High Input

Severity: low Safe to drive

What P0183 means

The ECM feeds a reference voltage to the fuel temperature sensor and reads the voltage drop to work out fuel temperature. The sensor is a thermistor: warmer fuel lowers its resistance and the signal voltage. P0183 sets when the signal stays above the expected range, as with an open circuit, a short to voltage or a failed sensor.

Symptoms

  • Check Engine light on
  • Poor fuel economy
  • Rough or uneven idle
  • Reduced engine performance
  • Hard starting
  • Long cranking before the engine starts

Possible causes

  1. Failed fuel temperature sensor
  2. Open circuit or poor connection in the sensor wiring
  3. Corroded or damaged connector terminals
  4. Signal wire shorted to voltage
  5. ECM input circuit fault (rare)

How to diagnose

  1. Scan for codes, note the freeze frame data, clear the code and see if it returns.
  2. Check fuel temperature in live data; a failed circuit often reads an implausible extreme such as −40°F/°C.
  3. Inspect the sensor, connector and harness for damage, corrosion, moisture and chafing.
  4. Unplug the sensor and check for about 5 V reference and a good ground with a multimeter.
  5. Measure the sensor resistance and compare it to the manufacturer's temperature chart.
  6. Test the signal wire for an open or a short to voltage back to the ECM.
  7. If the sensor and wiring are fine, test the ECM and its connectors.

Common fixes

  • Replace the fuel temperature sensor
  • Repair or replace the damaged wiring harness
  • Clean or replace the corroded connector
  • Reprogram or replace the ECM if it is confirmed faulty

Questions and answers

Can I drive with a P0183 code?

Usually yes, the car stays drivable. Fuel economy and starting may get worse, so diagnose it soon.

What most often causes P0183?

Most often it's the sensor itself, a broken wire or a corroded connector. Start by inspecting the plug and checking the signal with a multimeter.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.