P018D: Fuel Pressure Sensor B Circuit High
What to do
Ask for the connector to be checked first, including that it is actually plugged in and latched. A sensor left disconnected after fuel filter or fuel system work produces this code exactly, and finding that costs nothing.
Mention any recent servicing or fuel system work, however unrelated it seems.
Ask for the sensor's earth connection to be tested, not just its signal wire. A lost earth makes the signal read high and is easy to overlook.
If you can smell fuel, report it immediately — a leaking seal at this sensor is both a cause of connector corrosion and a fire risk.
What this code means
The second fuel pressure sensor's signal is above the highest voltage the circuit should produce.
High and open are indistinguishable from inside the module, because these inputs carry a pull-up that the module sees when nothing is loading the circuit. The measurement that separates them is made at the connector with the sensor unplugged, and it takes a minute.
On this sensor, corrosion causing an open circuit is the more likely of the two. Its location in the fuel line exposes the connector to road salt and standing water, and a terminal that has corroded until it no longer makes contact reads exactly like a wire shorted to a supply.
The trivial case deserves checking first, as always: a sensor left unplugged after fuel filter or fuel system work produces this precisely, and on a car recently in for service it is a genuinely common finding that costs nothing.
Beyond that, look for the ground. A sensor whose earth path has gone open floats its signal high, which is why the sensor's ground should be verified rather than assumed — it is easy to test and frequently skipped.
A sensor that has failed internally open is the honest last conclusion, and it does happen. It should simply not be the first, given how much cheaper everything above it is.
Likely causes
Start here
- Open circuit in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
- Sensor left disconnected after previous work · easy
- Open sensor ground circuit · moderate
- Faulty fuel rail pressure sensor · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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