P2407: Volkswagen EVAP pump-current instability

P2407 identifies intermittent or erratic leak-detection pump sensing in Volkswagen's 2014 CBTA/CBUA chart. The detailed criteria examine pump-current behavior in two different phases.

Reference measurement and pumping are separate observations

During the reference measurement, Volkswagen lists current fluctuation greater than 1 milliamp. During the pump phase, it lists a current drop exceeding 6 milliamps for at least three seconds. These are changes in current, not universal limits for the pump's total operating current.

The phase distinction is useful when a stationary electrical reading looks normal. A single steady measurement does not demonstrate that the current remained stable through either monitored phase.

Erratic sensing is not a measured vapor leak

The code belongs to the sensing behavior of the leak-detection system. It does not directly establish a loose fuel cap, a specific vapor leak size or a failed pump motor. Other rows in the book classify leak or flow results using different criteria.

Professional diagnosis should retain the event timing and use the correct EVAP test procedure to relate the current changes to system operation. The quick-reference table provides no connector pinout, pump replacement instruction or permission to pressurize the tank. It supports an instability diagnosis that still needs a physical cause established.

Source: Volkswagen manufacturer diagnostic chart, physical PDF page 80; physical PDF page 88.