Code Definition

P0188 — Fuel Temperature Sensor B Circuit High Input

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0188

P0188 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0188 is stored, the module has detected a signal or supply voltage higher than the expected operating range; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0188 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The P0188 fault code is set when the Engine Control Module (ECM) detects a higher than expected input signal from the Fuel Temperature Sensor B circuit. This sensor is responsible for measuring the temperature of the fuel within the vehicle. Fuel temperature can significantly impact aspects such as fuel density, vapourization rates, and the overall efficiency of the combustion process. A high input signal from the sensor may indicate a malfunction within the sensor itself, a short to power in the sensor circuit, or issues with the wiring or connectors. Such a condition can lead to the ECM rece...

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