What Does P0185 Mean?
The fuel temperature sensor A is providing an intermittent or erratic signal to the ECM. This sensor monitors fuel temperature to help the PCM calculate proper fuel delivery, as fuel density changes with temperature. The driver may notice occasional rough running, slight hesitation, or minor fuel economy fluctuations, especially during temperature transitions.
Common Causes
35%
Loose, corroded, or damaged wiring connector at the fuel temperature sensor A
25%
Chafed or intermittently shorting wiring in the fuel temperature sensor A circuit
20%
Failing fuel temperature sensor A with internal intermittent open or short
12%
Poor ground connection for the sensor circuit
8%
ECM connector pin damage or internal circuit fault
Diagnostic Steps
1
Monitor the fuel temperature sensor A PID in live data — look for sudden voltage spikes, dropouts, or erratic readings while tapping on the sensor and wiggling the connector.
2
Inspect the fuel temperature sensor A connector for corrosion, bent pins, or loose terminal lock tabs. Clean with electrical contact cleaner and verify the weatherpack seal is intact.
3
Back-probe the sensor signal wire at the ECM connector and compare to the sensor connector reading. A difference indicates a wiring fault between the two points.
4
Perform a wiggle test on the wiring harness from the sensor to the ECM while monitoring voltage — focus on areas where the harness passes near heat sources or sharp edges.
5
Measure sensor resistance at varying temperatures (typical NTC thermistor: ~2.4 kΩ at 68°F, ~300 Ω at 176°F). Compare to manufacturer specs and check for erratic resistance changes when tapping the sensor.
Estimated Repair Cost
$50 - $250
Parts + labor, varies by vehicle and location
The fuel temperature sensor A is providing an intermittent or erratic signal to the ECM. This sensor monitors fuel temperature to help the PCM calculate proper fuel delivery, as fuel density changes with temperature. The driver may notice occasional rough running, slight hesitation, or minor fuel ec...
The most common cause of P0185 (Fuel Temperature Sensor A Circuit Intermittent) is: Loose, corroded, or damaged wiring connector at the fuel temperature sensor A
Typical repair costs for P0185 range from $50 to $250, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Generally safe to continue driving. The ECM will use a default fuel temperature value. Minor fuel economy degradation may occur, but no immediate safety risk. Address when convenient to avoid potential long-term fuel delivery inaccuracies.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0185 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
