P0184
Fuel Temperature Sensor A Circuit Intermittent
The appearance of the standard OBD2 trouble fault code P0184 is an indicator that your vehicle ECU triggered a threshold alert for "Fuel Temperature Sensor A Circuit Intermittent". Understanding the root component breakdown helps avoid expensive diagnostic fees.
Driver's Summary
The diagnostic trouble code P0184 indicates an active fault in the fuel temperature sensor a circuit intermittent circuit or component. The most common signs are intermittent check engine light, erratic fuel trim changes. This code won't leave you stranded, but it indicates a real issue that will only get easier and cheaper to fix sooner rather than later.
Symptoms
Intermittent check engine light, erratic fuel trim changes
Common Causes
- Loose connection at the fuel temp sensor
- Frayed wiring shorting out occasionally
- Internally failing sensor
- Vibration causing loss of signal
How to Fix
- 1 Secure the electrical connector
- 2 Perform a wiggle test to locate wiring break
- 3 Replace the fuel temp sensor
- 4 Apply dielectric grease to contacts
Technical Explanation
P0184 is stored after the control module confirms the fault over multiple ignition cycles, ruling out transient electrical noise as the cause. The diagnostic runs during closed-loop operation only, ensuring the engine is at full operating temperature and the PCM's fuel trim feedback loop is active before confirming any out-of-range condition. After two failed drive cycles, the code transitions from a pending to a confirmed DTC, and the PCM activates the MIL. Clearing the code without repairing the fault will result in re-illumination within one to two complete drive cycles.
Is It Safe to Drive?
Code P0184 has minimal impact on immediate driving safety. However, the underlying loose connection at the fuel temp sensor issue will cause this vehicle to fail an emissions inspection and may gradually affect fuel economy if left unrepaired.
Mechanic's Pro Tip
Before replacing any component on P0184, spend 5 minutes inspecting the wiring harness and connector first — corrosion, chafed insulation, and backed-out pins cause the majority of these faults and cost nothing to fix. Use a multimeter to measure voltage drop across the connector pins under load; anything above 0.1V indicates excessive resistance that will cause intermittent failures even after replacing the sensor.
Connector repair: 50 - 100; Sensor replacement: 100 - 250