P2274: Volkswagen sensor-three signal stuck lean

P2274 identifies a bank-one, sensor-three oxygen signal classified as stuck lean in Volkswagen's 2014 CBTA/CBUA chart. The monitor considers response behavior, not only one low voltage sample.

The chart includes a corrective response context

Volkswagen describes the rear signal failing to oscillate below a reference in the 0.64–0.65-volt range, together with a 20-percent enrichment condition associated with the stuck-lean check. The short table does not fully document the control sequence, so these details should not be turned into a complete test routine.

The useful distinction is that the controller evaluates how the signal behaves in a defined fuel-control context. A single lean reading during normal operation does not reproduce that complete observation.

Sensor three is not sensor two

The same page lists P2270 for sensor two with a different reference. Retain the sensor-three identity and avoid copying a neighboring sensor's threshold merely because both descriptions say “stuck lean.”

The code does not independently establish that the oxygen sensor is defective or that the engine is genuinely lean under every condition. Professional diagnosis should compare the response evidence with the exact vehicle procedure. The quick-reference chart provides no cause ranking, leak-test instruction or replacement decision for this monitor.

Source: Volkswagen manufacturer diagnostic chart, physical PDF page 80; physical PDF page 86.