Possible Causes

WARNING: This page is about a different car, the 2002 Infiniti Q45. However, it is still accessible from the selected car via links, so may be relevant.

Malfunction is detected when improper voltage is sent to ECM from EVAP-CSPS. Possible causes are:

EVAP-CSPS circuit open or shorted.
EVAP-CSPS hose plugged or leaking.
Defective EVAP-CSPS.
Defective EVAP Canister Vent Control Valve (EVAP-CVCV).
Defective EVAP Canister Purge Volume Control Valve (EVAP-CPVCV).
Defective EVAP canister.
Hose between EVAP canister and water separator plugged or leaking.