Possible causes

– Leak Detection Pump (LDP) pressure hose obstructed
– Faulty Leak Detection Pump (LDP)
– Obstructed hose
– EVAP canister obstructed

When is the code detected?

Malfunction is detected when during system monitor test the Powertrain Control Module (PCM) detected a pinched EVAP hose

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Possible a noticeable fuel odor caused by the release of fuel vapors

P1486 JEEP Description

The Evaporative emissions system is design to prevent the escape of fuel vapors from the fuel system. Leaks in the system, ca allow vapors to escape into the atmosphere. The leak detection system tests for EVAP system leaks and blockage.

During the self-diagnostics, the Powertrain Control Module (PCM) first checks the Leak Detection Pump (LDP) for electrical and mechanical faults. If the first checks pass, the PCM then uses the LDP to seal the vent valve and pump air into the system to pressurize it. If a leak is present, the PCM will continue pumping the LDP to replace the air that leaks out. The PCM determines the size of the leak based on how fast/long it must pump the LDP as it tries to maintain pressure in the system.