Refer to Engine Controls Schematics
MAF Sensor, EVAP Components and EGR Valve
.
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 Open and the EVAP canister vent solenoid 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 Closed and the EVAP canister vent solenoid 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 or Closed states of the EVAP canister purge and vent valves.
Control Module Command | EVAP Canister Purge Solenoid | EVAP Canister Vent Solenoid |
|---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
Conditions for Running the DTC
| • | DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0440, P0442, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121, or 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 between 4-30°C (39-86°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
| • | Fuel tank pressure is less than -10 in. H2O. |
| • | The condition is present for as long as 30 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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 a damaged EVAP vent housing, a temporary blockage at the EVAP vent valve inlet or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem. To repair a blockage in the EVAP system, refer to Evaporative Emission System Cleaning .
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||
2 | Did DTC P0443, P0449, P0452 or P0453 set? | -- | Go to Step 3 | |||||||
3 | Inspect the 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 the 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 10 | ||||||
8 | Disconnect the EVAP vent hose from the EVAP vent solenoid. 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 vent solenoid. Refer to Evaporative Emission Vent 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 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 17 | ||||||
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |
