Table 1: | DTC P0455 Evaporative Emission (EVAP) System Large Leak Detected |
The control module tests the evaporative emission (EVAP) system for a large leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the control module commands the EVAP canister purge valve OPEN and the EVAP vent valve CLOSED . This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the control module commands the EVAP canister purge valve closed, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum level. If the system is unable to achieve the calibrated vacuum level, or the vacuum level increases too slowly, 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 Valve | EVAP Canister Vent Valve |
---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
This diagnostic procedure supports the following DTC:
DTC P0455 Evaporative Emission (EVAP) System Large Leak Detected
• | DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0300, P0402, P0404, P0405, P0406, P0443, P0452, P0453, P0462, P0463, P0488, P0502, P0506, P0507, P2195, and P2196 are not set. |
• | The ignition 1 voltage is between 11-16 volts. |
• | The barometric pressure (BARO) is more than 72 kPa. |
• | The start-up IAT minus the startup ECT is within 12°C (22°F). |
• | The start-up ECT minus startup IAT is within 50°C (90°F). |
• | The engine coolant temperature (ECT) and the intake air temperature (IAT) at start-up are between -5°C and +40°C (23°F and 140°F). |
• | The start-up IAT minus IAT are within 3°C (5°F). |
• | The purge enable time is less than 360 seconds. |
• | The engine run time is more than 1 second and less than 420 seconds. |
• | DTC P0455 runs once an ignition cycle when the above conditions are met. |
The ECM detects the EVAP system is not able to achieve or maintain vacuum during the diagnostic test.
• | 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. |
• | 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. |
• | To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light. Introducing smoke in 15 second intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner. |
• | A temporary blockage in the EVAP purge solenoid, purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair any restriction in the EVAP system. |
• | To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . |
• | Observe the Freeze Frame/Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set . This may assist in diagnosing the condition. |
• | For an intermittent condition, refer to Intermittent Conditions . |
The numbers below refer to the step numbers on the diagnostic table.
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.
This step verifies proper operation of the FTP sensor.
A normal operating FTP sensor should increase above 5 inches H20 and stop between 6 inches H20 and 7 inches H20.
This step tests the EVAP purge solenoid vacuum source between the EVAP purge solenoid and the Intake manifold for restrictions or blockages.
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 |
Important:
Is the floating indicator below the red flag? | -- | Go to Step 7 | Go to Step 3 | ||||||||||
3 |
Did you find and correct the condition? | -- | Go to Step 19 | Go to Step 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. The system flow will be less with higher temperatures.
Did you locate and repair a leak source? | -- | Go to Step 19 | Go to Step 5 | |||||||||||
5 |
Did you locate and repair a leak source? | -- | Go to Step 19 | Go to Step 6 | ||||||||||
Is the scan tool Fuel Tank Pressure parameter within the specified value of the J 41413-200 pressure/vacuum gage? | 1 in H2O | Go to Step 7 | Go to Step 15 | |||||||||||
Is the Fuel Tank Pressure sensor parameter more than the specified value? | 5 in H2O | Go to Step 8 | Go to Step 15 | |||||||||||
8 |
Is the Fuel Tank Pressure sensor parameter less than the specified value? | 1 in H2O | Go to Diagnostic Aids | Go to Step 9 | ||||||||||
Disconnect the EVAP purge vacuum source from the EVAP purge solenoid. Is the Fuel Tank Pressure parameter less than the specified value? | 1 in H2O | Go to Step 13 | Go to Step 10 | |||||||||||
10 | Disconnect the EVAP purge pipe from the EVAP purge solenoid. Is the Fuel Tank Pressure parameter less than the specified value? | 1 in H2O | Go to Step 16 | Go to Step 11 | ||||||||||
11 | Disconnect the EVAP purge pipe at the EVAP canister. Is the Fuel Tank Pressure parameter less than the specified value? | 1 in H2O | Go to Step 17 | Go to Step 12 | ||||||||||
12 | Disconnect the EVAP vapor pipe at the EVAP canister. Is the Fuel Tank Pressure parameter less than the specified value? | 1 in H2O | Go to Step 18 | Go to Step 14 | ||||||||||
13 | Repair the pinched or obstructed EVAP purge solenoid vacuum source. Did you complete the repair? | -- | Go to Step 19 | -- | ||||||||||
14 | Repair the pinched or obstructed EVAP vapor pipe. Did you complete the repair? | -- | Go to Step 19 | -- | ||||||||||
15 | Replace the fuel tank pressure (FTP) sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||
16 | Replace the EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||
17 | Repair the restriction in the EVAP purge pipe. Refer to Evaporative Emission System Hoses/Pipes Replacement . Did you complete the repair? | -- | Go to Step 19 | -- | ||||||||||
18 | Replace the EVAP canister. Refer to Evaporative Emission Canister Replacement . Did you complete the replacement? | -- | Go to Step 19 | -- | ||||||||||
19 |
Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
Is the floating indicator below the red flag? | -- | Go to Step 20 | Go to Step 4 | ||||||||||
20 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |