B1220 Code: Meaning, Symptoms, Causes & Fix

Overview

Code B1220 indicates a fault in Fuel Tank Pressure Sensor Circuit Open, typically within fuel delivery and pressure control.

Symptoms

hesitation under acceleration
reduced fuel economy
hard starting

Common causes

Broken terminal inside harness affecting fuel tank pressure sensor circuit open
Open circuit in wiring
Connector pin damage/corrosion or harness stress near related components

How to diagnose B1220

Confirm B1220 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to fuel tank pressure sensor circuit open for obvious defects.
Use a continuity test from module pin to component to identify opens/high resistance.
Check for related DTCs to identify the root-cause chain before replacing parts.
After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code B1220

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with B1220?

Most vehicles can be driven short-term with B1220, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

Repair obvious wiring/connector faults first to prevent repeat parts replacement.
Address the root fault mode (open) in the fuel tank pressure sensor circuit open circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify B1220 remains cleared under the conditions that originally set the code.

Fix options

Repair open circuit and secure connector lock.
Clear corrosion and protect terminals.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$220-$1100

Common mistakes when diagnosing B1220

Replacing parts without verifying voltage, ground, and signal integrity first.
Ignoring related stored/pending codes that indicate upstream faults.
Skipping post-repair verification drive cycle and readiness checks.

B1220 in common vehicles

B1220 appears across makes such as Mazda, Subaru, Lexus, Jeep. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes B1220?

B1220 is commonly set by open faults affecting fuel tank pressure sensor circuit open.

How much does it cost to fix B1220?

For B1220, repair costs are typically $220-$1100 depending on exact root cause, labor rates, and part quality.

Can I clear B1220 without repair?

You can clear B1220 temporarily, but the code usually returns until the underlying fault is corrected.