Workshop Manual

6E–321
6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0442 EVAP System Small Leak Detected
060RY00398
Circuit Description
The evaporative system includes the following
components:
B Fuel tank
B EVAP canister vent solenoid
B Fuel tank (vapor) pressure sensor
B Fuel pipes and hoses
B Vapor lines
B Fuel cap
B Evaporative emissions canister
B Purge lines
B EVAP canister purge solenoid
The evaporative leak detection diagnostic strategy is
based on applying vacuum to the EVAP system and
monitoring vacuum decay. The powertrain control
module (PCM) monitors vacuum level via the fuel tank
pressure sensor input. At an appropriate time, the EVAP
canister purge solenoid and the EVAP canister vent
solenoid are turned “ON”, allowing engine vacuum to
draw a small vacuum on the entire evaporative emissions
system. After the desired vacuum level has been
achieved, the EVAP canister purge solenoid is turned
“OFF”, sealing the system. A leak is detected by
monitoring for a decrease in vacuum level over a given
time period, all other variables remaining constant. A
small leak in the system will cause DTC P0442 to be set.
Conditions for Setting the DTC
B No TP sensor, ECT sensor, Tank pressure sensor, IAT
sensor, or MAP sensor DTCs set.
B BARO is more than 70 kPa.
B Engine speed is less than 1200 RPM.
B Fuel level is between 15% and 85%.
B Vehicle speed is less than 5 mph (8 km/h).
B The DTC P0440 diagnostic test has passed.
B A vacuum decay condition, indicating a small leak, is
detected during the diagnostic test.
Action Taken When the DTC Sets
B The PCM will ON the MIL after second trip with
detected fault.
B The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
B The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
B A history DTC P0442 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
B DTC P0442 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.