P0184 moderate

Fuel Temperature Sensor B Circuit

The P0184 code means the vehicle's onboard diagnostic system has detected: Fuel Temperature Sensor B Circuit. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$60 - $300 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Inaccurate fuel temperature readings on scan tool
  • Possible fuel delivery issues
  • Engine may run rough in extreme temperatures

Probable Causes (Ranked by Likelihood)

  • Faulty fuel temperature sensor B Very High
  • Damaged wiring or connector to sensor B High
  • Fuel contamination affecting sensor readings Moderate
  • PCM circuit fault Low

Step-by-Step Diagnostic Procedure

  1. Read fuel temperature sensor B PID on scan tool. Compare to ambient temperature with cold engine.

  2. Locate fuel temperature sensor B (typically on fuel rail or return line). Measure resistance.

  3. Inspect connector for fuel contamination or corrosion.

  4. Compare sensor B readings to sensor A (if equipped). They should be close when the engine is cold.

Frequently Asked Questions

What is fuel temperature sensor B?

Fuel temperature sensor B is a secondary fuel temperature sensor, commonly found on diesel engines to monitor fuel temperature at a different location than sensor A.

Why do diesel engines need fuel temperature sensors?

Diesel fuel density changes with temperature, affecting injection quantity. The PCM uses fuel temperature to adjust injection timing and duration.

Can I drive with P0184?

Yes, for short distances. The PCM will use a default fuel temperature value, but fuel delivery may not be optimized in extreme conditions.

Sources

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

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