Circuit Description

Evaporative leak detection strategy is based on applying vacuum to EVAP system and monitoring vacuum decay. Powertrain Control Module (PCM) monitors vacuum level by means of fuel tank vacuum sensor input. At a predetermined time, EVAP purge solenoid and EVAP vent solenoid are turned on. This allows engine vacuum to draw a small vacuum on entire EVAP system. Whenever a sufficient vacuum level cannot be achieved, a large leak or faulty EVAP purge solenoid is indicated.

Conditions for setting this DTC are as follows:

• Engine speed is 1700-4000 RPM.
• Engine coolant temperature and intake air temperature is 39-86°F(4-30°C) at engine start-up.
• Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor are within 39°F (4°C) at engine start-up.
• Barometric Pressure (BARO) is greater than 70 kPa.
• TP angle is 9-35 percent.
• Engine run time is greater than 2 minutes.
• No presence of Codes: P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121-P0123, P0125, P0131-P0134, P1133.
• EVAP solenoid is enabled.
• Fuel tank level is 15-85 percent.
• EVAP system is unable to achieve or maintain vacuum during diagnostic test. Amount of vacuum decay will vary with fuel level.