P0185 moderate

Fuel Temperature Sensor B Circuit Range/Performance

The P0185 code means the vehicle's onboard diagnostic system has detected: Fuel Temperature Sensor B Circuit Range/Performance. This is a moderate severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$60 - $300 (parts and labor)
Recommended Tool
ANCEL AD310 OBD-II Scanner

Best-selling code reader on Amazon. Reads and clears check engine codes on any 1996+ vehicle. Under $30.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Every Tech Needs This
AstroAI Digital Multimeter

Essential for diagnosing sensor codes, checking voltage, and testing circuits. Under $15 and pays for itself on the first job.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

  • Check Engine Light illuminated
  • Fuel temperature readings erratic or out of range
  • Possible fuel economy decrease
  • Engine performance may vary with temperature

Probable Causes (Ranked by Likelihood)

  • Degraded fuel temperature sensor B Very High
  • Poor sensor ground connection High
  • Contaminated fuel affecting sensor accuracy Moderate
  • PCM calibration issue Low

Step-by-Step Diagnostic Procedure

  1. Monitor fuel temp sensor B readings during a drive. Values should change gradually with engine warm-up.

  2. Compare sensor B to sensor A readings. Deviation greater than 15F (8C) at idle indicates a problem.

  3. Check sensor ground circuit resistance. Should be less than 0.5 ohms.

  4. If sensor reads correctly cold but drifts hot, replace the sensor.

Frequently Asked Questions

What does range/performance mean for a fuel temp sensor?

The sensor provides readings but they fall outside the expected range for current conditions, or the response is too slow.

Can bad fuel cause P0185?

Contaminated fuel with water or additives can affect sensor readings, but the sensor itself is the more likely cause.

Is P0185 common on diesel trucks?

Yes, diesel fuel temperature monitoring is critical for injection control, and these sensors degrade over time from high-pressure fuel exposure.

Sources

This page is built from documented references. Verify against your own service info before repair work.

Explore More

Search codes Vehicle-specific fixes Guides By make

Was this helpful?

Share carcodefinder.com with a friend who needs to decode their check engine light.

Browse by symptom → Read repair guides → Fixes by vehicle →