Fuel and air

P0184 — Fuel Temperature Sensor A Circuit Intermittent

Severity: low Safe to drive

What P0184 means

The PCM reads the fuel temperature sensor voltage to correct for fuel density and fine-tune the air-fuel mixture. P0184 sets when that signal drops out, jumps around, or goes out of range and then returns to normal. A poor connection is the most common cause, and the sensor itself is less often at fault.

Symptoms

  • Check Engine light on
  • Intermittent rough idle
  • Hesitation or stumbling on acceleration
  • Reduced fuel economy
  • Occasional stalling or brief power loss
  • Fluctuating fuel temperature readings on a scan tool

Possible causes

  1. Failing fuel temperature sensor
  2. Damaged or broken wiring in the harness
  3. Corroded or loose sensor connector terminals
  4. Loose connector at the fuel pump module
  5. Poor ground in the sensor circuit
  6. PCM fault (rare)

How to diagnose

  1. Read codes and freeze frame data, clear the code, and see if it returns
  2. Watch fuel temperature in live data: it should change smoothly and look realistic
  3. Inspect the sensor and fuel pump module connectors for corrosion, moisture, or bent terminals
  4. Wiggle the harness and connector with the engine running while watching the scan tool
  5. Measure sensor resistance and compare it to the manufacturer's spec at known temperatures
  6. Test signal and ground wires for opens and shorts, and check the 5V reference
  7. Check the harness near the fuel tank and any chafe points
  8. If everything tests good, consider a PCM fault

Common fixes

  • Clean and secure the connectors, applying dielectric grease
  • Repair or replace the damaged harness section
  • Replace the fuel temperature sensor (often part of the fuel pump module or fuel rail)
  • Reprogram or replace the PCM if all else checks out

Questions and answers

What does P0184 mean?

The PCM is getting an unstable, intermittent signal from the fuel temperature sensor circuit. It is usually caused by a poor connection or a worn sensor.

Can I drive with P0184?

Usually yes, but have the circuit checked soon. If the engine stalls or loses power, don't risk it and get it diagnosed.

How do I fix P0184?

Start by inspecting and cleaning the connectors and checking the wiring. If the wiring is good, replace the fuel temperature sensor.

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.