P2419: EVAP switching-valve circuit-low row contains conflicting fault wording

P2419 is labeled EVAP switching-valve control circuit low in the reviewed GM table. The row belongs to the conventional vented leak-detection system with fuel tank zone module, but its detailed text contains an important inconsistency.

What can be read reliably

The component heading names a circuit-low fault, and the threshold column specifies less than 0.5 ohm between output and controller ground. Those details are consistent with a low or ground-short signature.

However, the strategy and malfunction columns repeatedly describe an open circuit, apparently carrying wording from another row. The article therefore does not treat that open-circuit prose as a verified explanation of P2419. The exact driver-state and fault-class procedure should be confirmed in the applicable service information before a detailed test is designed.

Useful diagnostic boundaries remain

The row identifies the switching-valve electrical control circuit, excludes an EVAP-device communication fault, and lists 50 failures out of 63 samples at 250-millisecond intervals. It is classified Type B, two trips.

These facts distinguish the code from a direct proof of mechanical valve position or a measured fuel-vapor leak. A valve-performance conclusion cannot be drawn solely from this electrical code.

Preserve the circuit-low description and communication status, then use the vehicle-specific electrical procedure to resolve the abnormal path. Verification should establish correct switching-valve circuit behavior and no recurring monitor failure. The listed impedance is not an instruction for resistance testing an energized circuit, and the source does not mandate replacing the valve.

Source and applicability

The documented control architecture and calibration require confirmation for the vehicle being diagnosed. GM diagnostic table, PDF page 650.