Description
This diagnostic trouble code (DTC) tests for undesired intake manifold vacuum flow to the evaporative emissions (EVAP) system. The powertrain control module (PCM) seals the EVAP system by commanding the EVAP purge valve OFF (closed) and the EVAP vent valve ON (closed). The powertrain control module (PCM) monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. This DTC will set if the vacuum in the EVAP system is more than a predetermined value within a predetermined time.
Conditions for Running the DTC
| • | DTCs P0440, P0442, P0446, P0107, P0108, P0110, P0112, P0113, P0115, P0117, P0118, P0121, P0122, P0123, P0125, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, or P1122 are not set. |
| • | The system voltage is between 10-18 volts. |
| • | The startup engine coolant temperature (ECT) is between 4-30°C (39-86°F). |
| • | The startup intake air temperature (IAT) is between 4-30°C (39-86°F). |
| • | The fuel tank level is between 15-85 percent. |
| • | The barometric pressure (BARO) is more than 75 kPa. |
| • | The vehicle speed sensor (VSS) is less than 120 km/h (75 mph). |
Conditions for Setting the DTC
The PCM detects vacuum during a non-purge condition.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
The EVAP system tests run when the engine is first started and meets the Conditions for Running the DTC. An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve or a temporary blockage in the EVAP canister purge valve. To repair a blockage in the EVAP system refer to EVAP System Cleaning.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Emission Hose Routing Diagram and Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 | Are DTCs P0443, P0449, P0452 or P0453 also set? | -- | Go to Step 3 | |
3 |
Does the scan tool indicate fuel tank pressure within the specified range? | -0.5 to +0.5 in H2O | Go to Step 5 | Go to Step 4 |
4 |
Does the scan tool indicate fuel tank pressure within the specified range? | -0.5 to +0.5 in H2O | Go to Step 6 | Go to DTC P0453 |
5 |
Does the EVAP diagnostic station indicate an increase in vacuum? | -- | Go to Step 7 | Go to Diagnostic Aids |
6 | Replace the fuel tank pressure sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 8 | -- |
7 | Replace the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 8 | -- |
Does the scan tool indicate that the Service Bay Test has passed? | -- | Go to Step 9 | Go to Step 3 | |
9 | With a scan tool, select the review Info option. Does the scan tool indicate any DTCs that have not been diagnosed? | -- | System OK | |
