The Evaporative Emission (EVAP) System is used to store fuel vapors as to reduce the amount of unburned fuel from escaping into the atmosphere. The EVAP system consists of the EVAP canister, fuel tank pressure (FTP) sensor, EVAP lines and hoses, EVAP purge solenoid (normally closed), EVAP service port, EVAP vent solenoid (normally open) and fuel tank. The engine control module (ECM) monitors the EVAP system for circuit faults in the EVAP purge solenoid, EVAP vent solenoid and FTP sensor circuits. The ECM also monitors the EVAP for leaks between EVAP vent and purge solenoid. When certain conditions have been met, the ECM will perform an EVAP diagnostic test at idle with no vehicle speed. DTC P0455 will set if a vacuum cannot be pulled on the EVAP system during Phase D of the EVAP diagnostic system test indicating a large EVAP system leak or insufficient vacuum to EVAP purge solenoid.
• | DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0136, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0154, P0155, P0156, P0157, P0158, P0159, P0160, P0161, P0221, P0222, P0223, P0442, P0443, P0444, P0445, P0446, P0447, P0448, P0449, P0451, P0452, P0453, P0506, P0507, P1271, P1277, P1278, P1282, P1283, P1511, P1516, P1519, P1523, P1526, P1530, P1551, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128, P2138, P2176 are not set. |
• | The condition exists for 8 seconds or no change is detected for 4 seconds. |
• | The EVAP purge solenoid is commanded to a 12 percent duty cycle. |
• | The EVAP vent solenoid is commanded ON. |
• | The engine is at idle. |
• | The vehicle speed is 0 mph (0 kph). |
• | The engine load is less than 35 percent. |
• | The ignition 1 voltage is greater than 10 volts. |
• | The engine coolant temperature (ECT) at engine startup is between 4°C-55°C (40°F-131°F). |
• | The intake air temperature (IAT) is between 4°C-60°C (40°F-140°F). |
• | The long term FT cells learned (if not learned, engine must run longer than 16 minutes and 45 seconds). |
DTC P0455 diagnostic runs once during the EVAP diagnostic test once per ignition cycle. If DTC P0455 fails, the ECM will re-run the EVAP diagnostic test from the beginning and must fail P0455 again to set.
If an EVAP diagnostic test is aborted due to changing enabled criteria, the ECM will run the entire EVAP test up to three times per ignition cycle.
DTC P0455 will set if the FTP cannot be pulled greater than 2.02 volts, -4.88 mm Hg (-2.61 in H2O) during the EVAP diagnostic system test indicating a large EVAP leak.
• | 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. |
• | 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 non-emission related diagnostic. |
• | Clear the DTC with a scan tool. |
• | If DTC P0440, P0442, P0446, P0455 is set, EVAP special functions on the scan tool will not be allowed. Clear DTCs before performing these tests. |
• | The ECM uses the FTP sensor to detect the pressure of fuel vapor in the fuel tank during all parts of the EVAP diagnostic system test. Ensure the FTP sensor is not skewed by verifying FTP Sensor on the scan tool is between 1.3-1.7 volts with the ignition ON and the engine OFF. |
• | The following are possible causes of a large EVAP leak: |
• | The fuel cap is missing, incorrectly installed or leaking. |
• | The EVAP vent solenoid valve stuck open. |
• | The EVAP purge solenoid stuck closed/blocked or lack of manifold vacuum to solenoid. |
• | The EVAP line/hose connections are disconnected/leaking. |
• | The fuel sender O-ring is leaking. |
• | The FTP sensor seal is leaking. |
• | To help locate intermittent leaks, use the J 41413-200 J41413-100 Evaporative Emission 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. |
• | To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . |
• | Review the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to set occurs. This may assist in diagnosing the condition. |
• | 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 |
Did you find and correct the condition? | -- | Go to Step 16 | Go to Step 3 | ||||||||||
3 |
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 16 | Go to Step 4 | ||||||||||
4 |
Did you locate and repair a leak source? | -- | Go to Step 16 | Go to Step 5 | ||||||||||
5 |
Is the scan tool fuel tank pressure sensor parameter within the specified value of the J 41413-200 J41413-100 (J41413-200) pressure/vacuum gage? | 1 in H2O | Go to Step 6 | Go to Step 12 | ||||||||||
6 |
Is the fuel tank pressure sensor parameter more than the second specified value? | 10 in H2O 5 in H2O | Go to Step 7 | Go to Step 12 | ||||||||||
7 |
Is the fuel tank pressure sensor parameter less than the specified value? | 1 in H2O | Go to Diagnostic Aids | Go to Step 8 | ||||||||||
8 | Disconnect the EVAP purge pipe from the EVAP purge solenoid. Is the fuel tank pressure sensor parameter less than the specified value? | 1 in H2O | Go to Step 13 | Go to Step 9 | ||||||||||
9 | 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 14 | Go to Step 10 | ||||||||||
10 | 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 15 | Go to Step 11 | ||||||||||
11 | Repair the pinched or obstructed EVAP vapor pipe. Did you complete the repair? | -- | Go to Step 16 | -- | ||||||||||
12 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||||||
13 | Replace the EVAP purge solenoid. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 16 | -- | ||||||||||
14 | Repair the restriction in the EVAP purge pipe. Did you complete the repair? | -- | 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 |
Important: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results.
Does the J 41413-200 J41413-100 (J41413-200) pressure/vacuum gage remain constant? | 5 in H2O | Go to Step 17 | Go to Step 3 | ||||||||||
17 | Observe the fuel tank pressure sensor parameter with a scan tool. Is the scan tool fuel tank pressure parameter within the specified value of the J 41413-200 J41413-100 (J41413-200) pressure/vacuum gage? | 1 in H2O | Go to Step 18 | Go to Step 5 | ||||||||||
18 |
Does the pressure decrease? | -- | Go to Step 19 | Go to Step 8 | ||||||||||
19 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |