This is the description and diagnostics need to be done for this code.
This code has no effect on your current issue.
Roy
SYSTEM DESCRIPTION
The EVAP system includes the following components:
The fuel tank
The EVAP vent valve
The EVAP canister purge valve
The EVAP canister
The fuel pipes and hoses
The EVAP vapor and purge pipes
The EVAP fresh air vent hose
The fuel till cap
The EVAP SMALL LEAK TEST is based on applying vacuum to the EVAP system and monitoring the vacuum decay. The Powertrain Control Module (PCM) monitors the vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP canister purge valve and the EVAP vent valve are turned on, allowing engine vacuum to draw a small vacuum on the entire evaporative emission system. After the desired vacuum level has been achieved. The EVAP purge valve is turned off sealing the system. A leak is detected by monitoring for a decrease in the vacuum level over a specified time period, with all other variables remaining constant. A small leak in the system will cause DTC P0442 to be set.
CONDITIONS FOR RUNNING THE DTC
DTCs P0443 or P0449 are not active.
No TP, IAT, FTP, ECT, or MAP Sensor DTCs are set.
The system voltage is between 10-18 volts.
The DTC P0440 diagnostic test has passed.
The start-up ECT is not more than 4°C-30°C (39°F-86°F).
The start-up ECT is not more than 8°C (14°F) more than the IAT start-up temperature.
The start-up IAT not more than 4°C-30°C (39°F-86°F).
The start-up IAT is not more than 3°C (7°F) more than the ECT start-up temperature.
The fuel tank level is between 15-85 percent for a 0.040-0.060 inch leak.
The fuel tank level is between 30-85 percent for a 0.020 inch leak.
The BARO is more than 75 kPa.
The IAT is less than 30°C (86°F).
The VSS is less than 80 MPH.
CONDITIONS FOR SETTING THE DTC
A vacuum decay condition indicating a small leak is detected during the diagnostic test.
ACTION TAKEN WHEN THE DTC SETS
The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
CONDITIONS FOR CLEARING THE MIL/DTC
The PCM will turn OFF the MIL during the first trip in which the diagnostic has been run and passed.
The History DTC will clear when the PCM turns OFF the MIL.
The DTC can be cleared by using a scan tool.
DIAGNOSTIC AIDS
The following conditions will set DTC P0442:
A loose or malfunctioning fuel fill cap
Damaged EVAP purge or vapor pipes
A damaged EVAP fresh air vent hose
A malfunctioning EVAP vent valve
A damaged EVAP canister
A leaking fuel tank, fuel sender assembly. O-ring, or pressure relief valve
A leaking fuel filler neck or seal
Reviewing the Failure Records vehicle mileage after the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
1. The Powertrain On Board Diagnostic (OBD) System Check prompts you to complete some of the basic checks and store the Freeze Frame and Failure Records data on the scan tool if applicable.
15. The EVAP station is pressurizing a sensor that normally reads vacuum. The scan tool reads high pressure at 0 volts and high vacuum at 5 volts. The scan tool can only read a maximum pressure of 6.0 inches of Hg (0 volts), however the EVAP service station can pressurize the system to much higher pressures. The scan tool value should be within 0.5 inches Hg of the specified value.
Saturday, September 1st, 2018 AT 12:49 PM
