P2065: Fuel Level Sensor B Circuit

What it means

A general electrical fault is reported on the secondary fuel-level sensor (B) — vehicles with saddle tanks or auxiliary tanks use a second sender to cover the full tank volume.

How it works

Fuel level sensor B is the secondary sender used on some vehicles, such as those with a saddle tank or auxiliary tank. The control module monitors its electrical signal to calculate fuel level alongside the primary sender. P2065 indicates a general fault in the sensor B circuit, without specifying whether the sender or wiring is responsible.

Common causes

Most likely first.

1. Sender failed — float, swing arm, or rheostat
2. Harness or connector fault

Symptoms

• Check-engine light
• Fuel gauge may read inaccurately or erratically
• Low-fuel warning may not reflect the actual fuel level

How to diagnose it

1. Record freeze-frame data and check for related fuel sender codes to see whether the fault is intermittent or accompanied by another circuit issue.
2. Compare the displayed fuel level with the actual tank level and note whether the gauge or low-fuel warning behaves erratically.
3. Inspect sensor B's connector and accessible wiring for loose fit, corrosion, damage or chafing.
4. Use scan-tool data to compare sensor B's reading with the primary sender and the fuel gauge response, if available.
5. Test sensor B and its wiring for continuity and signal behavior using the manufacturer's procedure.

Common fixes

• Reconnect a loose sensor B plug or repair a poor terminal connection.
• Repair damaged wiring to the secondary sender.
• Replace a faulty fuel level sender B if testing confirms it is defective.
• Replace a damaged connector if its terminals cannot maintain a reliable connection.

Can I keep driving?

The vehicle is generally safe to drive, but the fuel gauge or low-fuel warning may be unreliable. Keep a generous fuel reserve and track refuelling until the sender circuit is repaired.