Circuit Description

1999 Chevrolet Chevy Express G1500, Van Cargo, 5.7 RSECTION 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 PCM detects a vacuum in the EVAP system when purge is not commanded.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.