How to diagnose an EVAP code in a vehicle?
How to diagnose an EVAP code in a vehicle?
VEHICLE APPLICATION: 2004 Grand Prix 3.8 AVG. REPORTED MILEAGE: 90,000 miles Apply vacuum to the disconnected tank hose at the evaporative canister. Test for fuel cap seal to tank filler neck. Test for leak at Fuel Tank Pressure (FTP) sensor. Replace FTP sensor as per TSB 04-06-04-025A. A customer rolls in with a check engine light.
How do you test the EVAP system monitor?
TEST PROCEDURE 1. Connect the Scan Tool to the data link connector (DLC). Use the Scan Tool to clear any stored DTC’s and to reset the Onboard Diagnostic Monitors. Bring up the Readiness Code for the EVAP System Monitor. 2. Start the engine (cold); IAT PID from 40-100ºF (this step requires a key “off” period of at least 8 hours). 3.
When does the EVAP system won’t run?
The engine temperature needs to match the air temperature in order to establish an accurate baseline for the testing. If the outside temperature is over 90° F, the fuel is too volatile and the EVAP system won’t even try to run its tests, though some of the other emissions systems may run their tests.
Why is my seconday EVAP monitor not ready?
I need to get my emmisions test to pass. The test has been rejected once. I have an Autotap and have been reading the emmission status through the ODB port. It says the EVAP & Seconday AIr System monitors are not ready. Show More Show Less
TEST PROCEDURE 1. Connect the Scan Tool to the data link connector (DLC). Use the Scan Tool to clear any stored DTC’s and to reset the Onboard Diagnostic Monitors. Bring up the Readiness Code for the EVAP System Monitor. 2. Start the engine (cold); IAT PID from 40-100ºF (this step requires a key “off” period of at least 8 hours). 3.
What happens if the EVAP test fails again?
If the decay rate is more than a calibrated value, the control module will rerun the test. If the test fails again, a DTC P0442 will set. If the evaporative emission (EVAP) vent system is restricted, fuel vapors will not be properly purged from the EVAP canister.
What should fuel level be for EVAP test?
The fuel level must be between 15% (1/4 tank) and 85% (3/4 tank) and steady. If the fuel level is changing, as with sloshing, the tests will not run. The PCM must also be clear of diagnostic trouble codes, to enable the EVAP testing.
Where is the service port for the EVAP test?
The EVAP service port is located in the EVAP purge pipe between the EVAP canister purge solenoid valve and the EVAP canister. The service port is identified by a green-colored cap. Conditions needed to run vacuum EVAP tests Fuel heated begins to produce pressure. A rise in temperature occurs as the fuel pump gives off heat.
