Detection Condition

PCM measures the fuel tank pressure (ftp1), which is the vacuum when a specified period has passed after fuel tank pressure has reached preprogrammed target pressure and purge control valve has been closed when monitoring conditions are met.

Threshold Value -  Fuel tank pressure (ftp1): -0.38-0.58 in. Hg (-1.3-1.95 kPa).

Monitoring Conditions

• Fuel tank pressure: more than -1.16 in. Hg.
• Fuel remaining: 35-85 percent of total capacity.
• Intake air temperature: 14-140°F (-10-60°C).
• Engine coolant temperature: 14-95°F (-10-35°C) when engine is first started.
• Atmospheric pressure: more than 20.5 in. Hg (69.7 kPa).
• Vehicle speed: 24.5-74.7 MPH.
• Engine speed: 1000-4000 RPM.
• Calculated load: 9-65 percent.
• Throttle opening angle is 3.1-12.5 percent (without traction control).
• Throttle opening angle is 3.1-10.2 percent (with traction control).

If fuel tank pressure is more than threshold, PCM determines that EVAP system is blocked or has a large leak. This is an intermittent monitor. MIL is illuminated when PCM detects malfunction condition in 2 consecutive drive cycles. Pending code is available if PCM detects malfunction condition during first drive cycle. Freeze frame data is available and DTC is stored in PCM memory.