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 solenoid valve OPEN and the EVAP vent solenoid 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 solenoid 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 decreases too rapidly, 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 solenoid valves.
Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve |
---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
This diagnostic procedure supports the following DTC:
DTC P0455 Evaporative Emissions (EVAP) System Large Leak
• | DTCs P0068, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0125, P0128, P0130, P0131, P0132, P0133, P0134, P0220, P0452, P0453, P0502, P0503, P0601, P0602, P0604, P0606, P060D, P060E, P0641, P1133, P1516, P1621, P2101, P2120, P2125, P2135, P2138, P2176 are not set. |
• | The engine is running. |
• | The EVAP canister purge solenoid valve is enabled. |
• | The ignition voltage is between 11-18 volts. |
• | The throttle position (TP) is between 7-35 percent. |
• | The barometric pressure (BARO) is more than 74 kPa. |
• | The fuel level is between 15-85 percent. |
• | The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F). |
• | The start-up intake air temperature (IAT) is between 4-30°C (39-86°F). |
• | The start-up ECT and IAT are within 8°C (14.4°F) of each other. |
• | The vehicle speed sensor (VSS) is less than 137 km/h (85 mph). |
• | DTC P0455 runs once per trip when the above conditions are met. |
The EVAP system is not able to achieve or maintain vacuum of 10 inches H2O for 30 seconds during the diagnostic 5.5-minute 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. |
• | A loose, incorrect, missing, or damaged fuel cap can cause this DTC to set. |
• | 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. |
• | A temporary blockage in the EVAP canister purge solenoid valve, 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 . |
• | Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition. |
• | For intermittent conditions refer to Intermittent Conditions . |
The numbers below refer to the step numbers on the diagnostic table.
This test verifies that the EVAP canister purge solenoid valve is electrically functional.
This test verifies that the EVAP canister vent solenoid valve is electrically functional.
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 test verifies that the FTP sensor is accurate. An FTP sensor that does not correctly respond to vacuum, or pressure may cause this DTC to set.
Step | Action | Values | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics or Evaporative Emissions Hose Routing Diagram Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||||
2 |
Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 3 | ||||||||||
Do you hear or feel a clicking from the EVAP canister purge solenoid valve when it is commanded to 50 percent? | -- | Go to Step 4 | Go to Step 5 | |||||||||||
Command the EVAP canister vent solenoid valve ON and OFF with the scan tool. Do you hear or feel a click as the EVAP canister vent solenoid valve is commanded ON and OFF? | -- | Go to Step 9 | Go to Step 7 | |||||||||||
5 |
Does the test lamp illuminate? | -- | Go to Step 6 | Go to Step 25 | ||||||||||
6 |
Does the test lamp illuminate or pulsate when the EVAP canister purge solenoid valve is commanded to 50 percent and turn OFF when the EVAP canister purge solenoid valve is commanded to 0 percent? | -- | Go to Step 20 | Go to Step 18 | ||||||||||
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 26 | ||||||||||
8 |
Does the test lamp illuminate? | -- | Go to Step 21 | Go to Step 19 | ||||||||||
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.
Did you locate and repair a leak source? | -- | Go to Step 34 | Go to Step 10 | |||||||||||
10 |
Did you locate and repair a leak source? | -- | Go to Step 34 | Go to Step 11 | ||||||||||
Is the scan tool Fuel Tank Pressure Sensor parameter within the specified value of the J 41413-200 pressure/vacuum gage? | 1 in H2O | Go to Step 12 | Go to Step 22 | |||||||||||
12 |
Is the Fuel Tank Pressure Sensor parameter more than the second specified value? | 10 in H2O 5 in H2O | Go to Step 13 | Go to Step 22 | ||||||||||
13 |
Is the Fuel Tank Pressure Sensor parameter Less than the specified value? | 1 in H2O | Go to Diagnostic Aids | Go to Step 14 | ||||||||||
14 | 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 24 | Go to Step 15 | ||||||||||
15 | 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 29 | Go to Step 16 | ||||||||||
16 | 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 27 | Go to Step 17 | ||||||||||
17 | 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 31 | Go to Step 28 | ||||||||||
18 | Test the control circuit of the EVAP canister purge solenoid valve for an open or for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 23 | ||||||||||
19 | Test the control circuit of the EVAP canister vent solenoid valve for an open or for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 34 | Go to Step 23 | ||||||||||
20 | Test for an intermittent and for a poor connection at the EVAP canister purge solenoid valve. 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 34 | Go to Step 29 | ||||||||||
21 | Test for an intermittent and for a poor connection at the EVAP canister vent solenoid valve. 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 34 | Go to Step 30 | ||||||||||
22 | 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 34 | Go to Step 32 | ||||||||||
23 | Test for an intermittent and for a poor connection at the control module. 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 34 | Go to Step 33 | ||||||||||
24 | Repair the pinched or obstructed EVAP canister purge solenoid valve vacuum source. Did you complete the repair? | -- | Go to Step 34 | -- | ||||||||||
25 |
Did you complete the repair? | -- | Go to Step 34 | -- | ||||||||||
26 | Repair the open or short to ground in the ignition 1 voltage circuit of the EVAP canister vent solenoid valve . Refer to Wiring Repairs in Wiring Systems. Replace the fuse as necessary. Did you complete the repair? | -- | Go to Step 34 | -- | ||||||||||
27 | Repair the restriction in the EVAP purge pipe. Refer to Evaporative Emission System Cleaning . Did you complete the repair? | -- | Go to Step 34 | -- | ||||||||||
28 | Repair the restriction in the EVAP vapor pipe. Did you complete the repair? | -- | Go to Step 34 | -- | ||||||||||
29 | Replace the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 34 | -- | ||||||||||
30 | Replace the EVAP canister vent solenoid valve. Refer to Evaporative Emission Canister Vent Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 34 | -- | ||||||||||
31 | Replace the EVAP canister. Refer to Evaporative Emission Canister Replacement . Did you complete the replacement? | -- | Go to Step 34 | -- | ||||||||||
32 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 34 | -- | ||||||||||
33 | Replace the powertrain control module (PCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 34 | -- | ||||||||||
34 |
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? | 5 in H2O | Go to Step 35 | Go to Step 2 | ||||||||||
35 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |