Circuit Description

PCM monitors amount of vacuum/pressure in EVAP system by monitoring fuel tank pressure sensor signal. PCM seals the EVAP system by commanding the EVAP purge solenoid off and EVAP vent valve on. PCM monitors fuel tank pressure sensor in order to determine if EVAP purge solenoid is leaking vacuum to EVAP system. This DTC sets if vacuum in EVAP system is greater than a predetermined value within a predetermined time.

DTC will set when following conditions are present:

• DTCs P0107, P0108, P0112, P0113, P0121, P0122, P0123, P0420, P0430, P0500, P0502, P0503, P1112, P1114, P1115 and HO2S related DTCs not set.
• Ignition voltage 10-17 volts.
• BARO pressure greater than 75 kPa.
• Fuel level 15-85 percent of full capacity.
• ECT and IAT 39-86°F (4-30°C).
• Start-up ECT and IAT are within 16°F (9°C) of each other.
• EVAP purge solenoid duty cycle is zero percent.
• TP angle between zero and 99 percent.
• EVAP system develops a vacuum greater than a predetermined value when purge is not commanded.