Circuit Description

Powertrain Control Module (PCM) uses fuel level input from instrument panel cluster to calculate expected vapor pressures within fuel system. Vapor pressure varies as fuel level changes.

Conditions for setting this DTC are as follows:

• Fuel level has not changed greater than 1.6 percent (4 counts) in 120 miles.
• DTC P1601 is set and vehicle has been driven for greater than 120 miles.