Vehicle Application: 2001 Hyundai Elantra 2.0L
Customer Concern: Check engine light is on with a code P0442 small leak detected.
Tests/Procedures: 1. Check the Canister Closed Valve (CCV) (next to the canister) and verify their is 12 volts on the Blue/Orange wire. Ground the solid Blue wire to verify the solenoid will close and hold vacuum.
2. Check the purge solenoid (under the hood next to the intake manifold, passenger side). Verify there is battery voltage on the solid Blue wire. Ground the solid Green wire and verify the purge solenoid will open.
3. To run an Evaporative Emission Control System (EVAP) test, energize the canister closed valve to seal the system, start the vehicle and tap to ground the Green wire at the purge solenoid to pull the system into a vacuum. Monitor the fuel tank pressure sensor voltage, (the pressure sensor is located next to the fuel tank) verify the voltage starts out at 2.5v and will drop down to about 1 V.
4. When the voltage drops to 1 V, release the ground from the purge solenoid and verify that the voltage will stay steady at around 1 V, it will slowly rise about a volt every 5 to 10 in seconds.
5. If voltage rises quickly, check for a small leak. If voltage stays steady, no problems at this time.
Potential Causes: Canister
CCV
Hose
Diagnostic Codes: P0442
Possible Causes Setting Conditions
Canister Purge valve is damaged, leaking or it has failed
Charcoal canister is loaded with fuel or moisture
Fuel filler cap loose, cross-threaded, incorrect part or damaged
Fuel tank is cracked (leaking), or a leak exists in the 'O' ring
Fuel tank pressure sensor has failed
Fuel vapor line(s), fuel pipes or hoses damaged or leaking
Purge solenoid or vent solenoid damaged, leaking or sticking
PCM has failed
DTC P0441,P0443, P0451, P0452 and P0453 not set; Ignition "off" requirement of 5 hours met, engine started (cold), IAT signal from 37-105ºF at startup, system voltage from 10-16v, altitude less than 8,200 feet, fuel level from 15-85%, vehicle driven for 20 minutes, and the PCM detected a large leak (more than 0.040â€) somewhere in the EVAP system. The PCM closes the Canister Close Valve (CCV) at the charcoal canister to seal off the Evaporative Emission (EVAP) system and then opens the purge control valve (PCSV) to generate vacuum in the fuel tank. After vacuum generation, the PCM measures the pressure differential curve in the fuel tank. The PCM sets DTC P0442 if the vacuum generated within a monitoring period increases above a defined threshold.
This code sets in 2 Trip(s).
This code will turn on the MIL (Malfunction Indicator Lamp)
