P0187
Fuel Temperature Sensor B Circuit Low Input
Lowsensor
Overview
The P0187 diagnostic trouble code means the PCM has identified a fuel temperature sensor b circuit low input problem. This code indicates that a sensor or its circuit is not providing expected readings to the engine management system. Faulty sensor data can cause the PCM to make incorrect adjustments, affecting engine performance.
Symptoms
- Engine running rough
- Erratic engine behavior
- Incorrect gauge readings
- Check Engine Light (MIL) illuminated
Common Causes
- Wiring issues (open, short, or high resistance)
- Faulty PCM (Powertrain Control Module)
- Poor ground connection for sensor
- Incorrect sensor installed
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Locate the specific sensor referenced by the code
- 3Inspect the sensor connector for corrosion, damage, or loose pins
- 4Test the sensor output using a multimeter or scan tool live data
- 5Check the wiring between the sensor and the PCM for opens or shorts
Estimated Repair Cost
$75 — $350
Cost varies by vehicle, location, and repair shop. Includes parts and labor.
Commonly Affected Vehicles
Honda CivicChevrolet CruzeMazda 3Hyundai Elantra
Related Codes
More Sensor Codes
P0070Ambient Air Temperature Sensor Circuit
LowP0071Ambient Air Temperature Sensor Range/Performance
LowP0072Ambient Air Temperature Sensor Circuit Low
LowP0073Ambient Air Temperature Sensor Circuit High
LowP0074Ambient Air Temperature Sensor Circuit Intermittent
LowP0095Intake Air Temperature Sensor 2 Circuit
LowFrequently Asked Questions
Most automotive sensors last 80,000-150,000 miles, though this varies by sensor type and driving conditions. Oxygen sensors and temperature sensors tend to degrade gradually over time.