P2400 Buick Evaporative Emission (EVAP) System Leak Detection Pump Control Circuit / Open

P2401 Buick Evaporative Emission System Leak Detection Pump Control Circuit Low

Possible causes
– Faulty Vacuum Pump Module
– Vacuum Pump Module harness is open or shorted
– Vacuum Pump Module circuit poor electrical connection.
– Faulty Engine Control Module (ECM)
What about the obd code?
To determine leak criterion (Reference pressure), vacuum pump creates negative pressure in canister pump module through 0.02 inch orifice and pressure is measured. If the conditions are not met, Engine Control Module (ECM) the code will be set.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P2401 Buick Description

5 hours* after the ignition switch is turned OFF, the electric vacuum pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The Engine Control Module (ECM) monitors for leaks and actuator malfunctions based on the EVAP pressure.

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera