Drive with caution — fix soon.
This code means the computer has detected a general malfunction in the fuel temperature sensor 'B' circuit, a second sensor used on some vehicles to monitor fuel temperature. The cause is usually a failed sensor, damaged wiring, or a poor connector, just like the 'A' circuit codes. Common fixes include repairing the wiring or connector, or replacing the affected fuel temperature sensor.
$110 – $360
Varies by vehicle and root cause.
Yes, in most cases you can drive normally since this fault rarely affects everyday performance. Still, it's wise to have it diagnosed within a week or two so a minor sensor or wiring issue doesn't get worse.
Most repairs fall between $110 and $360. A wiring or connector repair is cheaper, while replacing the 'B' fuel temperature sensor adds parts and labor depending on the vehicle.
It's a moderate-severity code. It generally won't leave you stranded, but since the sensor helps the engine run efficiently, fixing it keeps your fuel economy and emissions in good shape.
Both are fuel temperature sensor circuit malfunctions, but P0181 refers to sensor 'A' and P0186 refers to a second sensor, 'B'. Some vehicles use two fuel temperature sensors, and this code points specifically to the second circuit.