System Description
This DTC tests the evaporative emission (EVAP) system for a restricted or blocked EVAP vent path. The control module commands the EVAP canister purge solenoid valve Open and the EVAP canister vent solenoid valve Closed. This allows vacuum to be applied to the EVAP system. Once a calibrated vacuum level has been reached, the control module commands the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Open. The control module monitors the fuel tank pressure (FTP) sensor for a decrease in vacuum. If the vacuum does not decrease to near 0 inches H2O in a calibrated time, this DTC sets.
The following table illustrates the relationship between the ON and OFF states, and the Open and Closed states of the EVAP canister purge and vent solenoid valves.
Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve |
|---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
Conditions for Running the DTC
| • | DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0442, P0443, P0449, P0452, P0453, P0455, P1106, P1107, P1111, P1112, P1114, P1115, P1121, P1122 are not set. |
| • | The ignition voltage is between 10-18 volts. |
| • | The barometric pressure (BARO) is more than 75 kPa. |
| • | The fuel level is between 15-85 percent. |
| • | The engine coolant temperature (ECT) is less than 30°C (86°F). |
| • | The intake air temperature (IAT) is between 4-30°C (39-86°F). |
| • | The start-up ECT and IAT are within 9°C (16°F) of each other. |
| • | The vehicle speed sensor (VSS) is less than 121 km/h (75 mph). |
Conditions for Setting the DTC
The FTP does not increase a calibrated amount during a calibrated period of time.
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
| • | An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem. |
| • | For intermittent conditions, refer to Intermittent Conditions . |
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Evaporative Emissions Hose Routing Diagram | ||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||
2 | Are any DTCs other than P0446 set? | -- | Go to Step 3 | |||||||
3 | Inspect the evaporative emission (EVAP) system for the following conditions:
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 4 | ||||||
4 |
Is the fuel tank pressure sensor parameter within the specified range? | -1 to +1 in H2O | Go to Step 5 | Go to Step 10 | ||||||
5 |
Important: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results.
Is the Fuel Tank Pressure Sensor parameter less than the second specified value? | 5 in H2O 1 in H2O | Go to Step 6 | Go to Step 8 | ||||||
6 |
Is the FTP parameter on a scan tool within the specified value of the vacuum/pressure gage on the J 41413-200 until the vacuum reached the abort limit on a scan tool. | 1 in H2O | Go to Step 7 | Go to Step 10 | ||||||
7 | Did the FTP parameter on a scan tool display more than the specified value? | 3.2 V | Go to Diagnostic Aids | Go to Step 13 | ||||||
8 | Disconnect the EVAP vent hose from the EVAP canister vent solenoid valve. Is the Fuel Tank Pressure Sensor parameter less than the specified value? | 1 in H2O | Go to Step 14 | Go to Step 9 | ||||||
9 | Disconnect the EVAP vent hose from the EVAP canister. Is the Fuel Tank Pressure Sensor parameter less than the specified value? | 1 in H2O | Go to Step 12 | Go to Step 15 | ||||||
10 | Test for an intermittent and for a poor connection at the fuel tank pressure (FTP) sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 11 | ||||||
11 | Test the low reference circuit of the FTP sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 13 | ||||||
12 | Repair the pinched or restricted EVAP vent hose. Did you complete the repair? | -- | Go to Step 16 | -- | ||||||
13 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
14 | Replace the EVAP canister vent solenoid valve . Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
15 | Replace the EVAP canister. Refer to Evaporative Emission Canister Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||
16 | Perform the Service Bay Test. Refer to Service Bay Test . Does the scan tool indicate that the Service Bay Test passed? | -- | Go to Step 17 | Go to Step 3 | ||||||
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |||||||
