P1495A EVAP Leak Monitor Pinched Hose Found

NAME OF CODE
Leak Detection Pump Solenoid CKT

WHEN MONITORED
Ignition on and battery voltage greater than 10.4 volts.

SET CONDITION
The state of the solenoid circuit does not change.

THEORY OF OPERATION
The leak detection assembly incorporates two primary functions: It detects a leak in the evaporative system and seals the evaporative system so the leak detection test can be run.
The primary components within the assembly are a three-port leak detection solenoid that activates both of the functions described above, a pump containing a leak detection pump switch that monitors pump movement, two check valves and a spring diaphragm, and a canister vent valve seal containing a spring-loaded vent seal salve. When the solenoid is energized, it allows engine vacuum to enter the pump and draw the diaphragm up, thus allowing atmospheric pressure to enter the pump cavity. When the solenoid is de-energized, it vents the engine vacuum thus permitting the spring to drive the diaphragm down, forcing air out of the pump cavity into the vent system. When the solenoid is energized ad de-energized, the cycle is repeated, which creates flow in a typical diaphragm pump fashion.
After passing the leak detection phase of the test, system pressure is maintained until the purge system is activated, in effect creating a leak. If the cycle rate increases due to flow of the purge system, the test is passed and the diagnostic test is complete. If not, there is an obstruction in the system

POSSIBLE CAUSES
- Open or shorted LDP solenoid control circuit
- Leak detection pump solenoid failure
- Open fused ignition switch Output