Test Description
WARNING: This page is about a different car, the 2004 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step verifies that a failure condition is active.
- 4: Introducing smoke in 15 second intervals may allow smaller leak areas to be more noticeable. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
- 6: This step verifies proper operation of the fuel tank pressure (FTP) sensor.
- 7: A normal operating FTP sensor should increase above 5 inches of H20 and stop between 6 inches of H20 and 7 inches of H20.
- 9: This step tests the EVAP canister purge solenoid valve vacuum source between the EVAP canister purge solenoid valve and the intake manifold for restrictions or blockages.
DTC P0455
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Evaporative Emissions (EVAP) Hose Routing Diagram | ||||
| 1 | Did you perform the Diagnostic System Check-Engine Controls? | - | Go to Step 2 | Go to Diagnostic System Check - Engine Controls |
| 2 |
|
- | Go to Step 23 | Go to Step 3 |
| 3 |
IMPORTANT:
Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
|
- | Go to Step 6 | Go to Step 4 |
| 4 |
IMPORTANT:
Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. System flow will be less with higher temperatures.
|
- | Go to Step 23 | Go to Step 5 |
| 5 |
|
- | Go to Step 23 | Go to Step 6 |
| 6 |
|
1 in H2O | Go to Step 7 | Go to Step 15 |
| 7 |
|
10 in H2O 5 in H2O |
Go to Step 8 | Go to Step 15 |
| 8 |
|
1 in H2O | Go to Step 9 | Go to Step 11 |
| 9 |
|
1 in H2O | Go to Step 10 | Go to Step 15 |
| 10 | Did the FTP parameter on a scan tool display more than the specified value? | 3.2 V | Go to Diagnostic Aids | Go to Step 20 |
| 11 | Disconnect the EVAP purge vacuum source from the EVAP canister purge solenoid valve. Is the Fuel Tank Pressure sensor parameter less than the specified value? |
1 in H2O | Go to Step 17 | Go to Step 12 |
| 12 | Disconnect the EVAP purge pipe from the EVAP canister purge solenoid valve. Is the Fuel Tank Pressure sensor parameter less than the specified value? |
1 in H2O | Go to Step 17 | Go to Step 13 |
| 13 | Disconnect the EVAP purge pipe at the EVAP canister. Is the Fuel Tank Pressure sensor parameter less than the specified value? |
1 in H2O | Go to Step 19 | Go to Step 14 |
| 14 | Disconnect the EVAP vapor pipe at the EVAP canister. Is the Fuel Tank Pressure sensor parameter less than the specified value? |
1 in H2O | Go to Step 22 | Go to Step 18 |
| 15 | 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 23 | Go to Step 16 |
| 16 | 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 23 | Go to Step 20 |
| 17 | Repair the pinched or obstructed EVAP purge solenoid valve vacuum source. Did you complete the repair? |
- | Go to Step 23 | - |
| 18 | Repair the pinched or obstructed EVAP vapor pipe. Did you complete the repair? |
- | Go to Step 23 | - |
| 19 | Repair the restriction in the EVAP purge pipe. Did you complete the repair? |
- | Go to Step 23 | - |
| 20 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement
. Did you complete the replacement? |
- | Go to Step 23 | - |
| 21 | Replace the EVAP canister purge solenoid valve. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement (L36)
or Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement (L67)
. Did you complete the replacement? |
- | Go to Step 23 | - |
| 22 | Replace the EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement
. Did you complete the replacement? |
- | Go to Step 23 | - |
| 23 | Perform the Service Bay Test. Refer to Service Bay Test
. Does the scan tool indicate that the Service Bay Test passed? |
- | Go to Step 24 | Go to Step 3 |
| 24 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? |
- | Go to Diagnostic Trouble Code (DTC) List | System OK |