EVAP System Diagnostics

Diagnostic Chart:

Locations View:

The PCM monitors the following EVAP system electrical components for low and high voltage faults.
^ Fuel tank pressure sensor
^ EVAP purge solenoid
^ EVAP vent solenoid

As part of the On-board Diagnostics Second-generation (OBD II)
requirements, the government mandates that all automobile manufactures detect a 0.020 inch or greater diameter leak in the EVAP system. To comply, the PCM monitors the EVAP system for large and small leaks and whether the EVAP purge and vent solenoid valves are stuck closed or open.

IMPORTANT: The flowchart consists of a series of tests run by the PCM which describes the entire EVAP DIAGNOSTIC TEST. Each step the PCM performs is dependent on the accuracy of the fuel tank pressure sensor. The FUEL TANK PRESS. SENSOR reading on Scan tool with ignition On, engine off and fuel cap removed should read between 2.35 and 2.85 volts.