B1220 code definition

The B1220 trouble code indicates an incomplete (or "open") circuit has been detected in the vehicle's fuel tank pressure sensor.

What the B1220 code means

The fuel tank pressure sensor detects leaks in the tank and aids the vehicle's Evaporative Emissions (EVAP) system in vaporizing fuel to help lower pollution. In the case of an incomplete pressure sensor circuit, this system will be weakened.

What causes the B1220 code?

Faulty, disconnected or damaged wiring is most often the case for an incomplete sensor circuit. The fuel tank pressure sensor circuit itself may be faulty. If this is the case, it should be promptly replaced.

What are the symptoms of the B1220 code?

The B1220 code typically results in harsher exhaust and engine noise, a stronger gas smell when the engine is active, decreased fuel efficiency and the sensor's inability to regulate and report issues with fuel vapour in the fuel tank. A B1220 trouble code will be logged on the vehicle's diagnostic computer and a check engine lamp will be illuminated to alert the vehicle operator to the problem.

How does a mechanic diagnose the B1220 code?

A mechanic can verify the B1220 code first by using an OBD-II code reader to read any stored codes on the vehicle's computer. The wiring should be thoroughly inspected for signs of disconnection or damage, preferably using a voltmeter in order to precisely pinpoint the area where the circuit stops. Any other reported codes relating to the fuel tank pressure should be taken under consideration as well.

Common mistakes when diagnosing the B1220 code

The body-related trouble codes are often specific to certain models of vehicle. One code may carry different descriptions depending on the particular make of car. As a result, one body-related concern may be replaced mistakenly in lieu of the actual reported issue.

How serious is the B1220 code?

Depending on the severity of the pressure sensor circuit malfunction, the vehicle's emissions may be more visible and pollutant. Although this shouldn't significantly impact the vehicle's drivability, it can make the vehicle's operation a lot dirtier. It is recommended that a B1220 code be resolved as soon as possible.

What repairs can fix the B1220 code?

If any of the wiring or components have been identified as being faulty, damaged, disconnected or faulty in the fuel tank pressure sensor circuit, they should be repaired or replaced accordingly. In some cases, a fuel tank pressure sensor circuit issue may be caused by a vapour lock problem and an improperly secured fuel cap. Leave the fuel cap open for an hour then secure it tightly.

Retest the vehicle after repairs have been completed to ensure the problem has gone away. If the code returns, it is a sign that not all of the causes were solved during the first round of repairs.

Additional comments for consideration regarding the B1220 code

B-class trouble codes are often specific to certain specific types of vehicle. The meaning of a B1220 code may vary depending on the specific make of car.

Need help with a B1220 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as B1220 OBD-II Trouble Code: Fuel Tank Pressure Sensor Circuit Open and was authored by Conor Fynes.


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