For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC P0455: Evaporative Emission (EVAP) System Large Leak

### Circuit/System Description

The engine control module (ECM) tests the evaporative emission (EVAP) system for a large leak or a restriction in the purge path. When the conditions for running are met, the ECM commands the EVAP canister purge solenoid valve OPEN and the EVAP vent solenoid valve CLOSED, allowing engine vacuum to enter the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor signal in order to determine the EVAP system is able to reach a predetermined vacuum level within a set amount of time. This turbocharged engine is equipped with a one-way flow check valve that prevents boost pressure from entering the purge line and EVAP system.

### Conditions for Running the DTC

• | DTCs P0100, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0443, P0446, P0449, P0496, P0452, P0453, P0502, P0562, P0563, P0601, P0602, P0606, P2122, P2123, P2127, P2128 are not set.

• | The ignition voltage is between 11-18 volts.

• | The barometric pressure (BARO) is more than 68 kPa.

• | The fuel level is between 15-85 percent.

• | The intake air temperature (IAT) is between 2-32°C (35.6-90°F).

• | The start-up ECT and IAT are within 9°C (16.2°F) of each other.

• | The vehicle speed sensor (VSS) is less than 1.7 km/h (2 mph).

• | The engine is idling.

• | DTC P0455 will attempt to run up to 10 times until it successfully completes.

• | DTC P0455 completes one test per cold start within 10 minutes of start-up.

### Conditions for Setting the DTC

The EVAP system is not able to achieve or maintain vacuum for up to 4 times during the diagnostic test.

### Action Taken When the DTC Sets

DTC P0455 is a Type B DTC.

### Conditions for Clearing the MIL/DTC

DTC P0455 is a Type B DTC.

### Diagnostic Aids

• | A loose, missing, incorrect, or damaged fuel fill cap may cause this DTC to set.

• | To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT . 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.

• | 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.

• | A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for the vacuum decay, this type of leak may be detected.

• | If a small leak is difficult to find, it may be necessary to remove the EVAP components and leak test them one at a time.

• | The turbocharged engine is equipped with a one-way flow check valve that will prevent boost pressure from entering the purge line and the EVAP system. This check valve will also prevent flow from the J 41413-200 from the purge valve into the EVAP system.

### Reference Information

#### Schematic Reference

• | Evaporative Emissions Hose Routing Diagram

• | Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Evaporative Emission Control System Description

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

#### Special Tools

• | GE-41415-50 Fuel Tank Cap Adapter

• | J 41413-200 Evaporative Emission System Tester (EEST)

• | J 41413-SPT High Intensity White Light

### Circuit/System Testing

Important:

• | Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.

• | Refer to the J 41413-200 operation manual for detailed instructions in Evaporative Emission System Diagnosis.

1. Connect the J 41413-200 nitrogen/smoke hose to the J 41413-311 brass cone adapter. Disconnect the hose at the fuel cap end of the GE-41415-50 . Connect the J 41413-311 to the disconnected hose on the GE-41415-50 . Install the GE-41415-50 filler neck end only to the vehicle.
2. Seal the system and use the flow meter on the J 41413-200 , calibrated to 0.51 mm (0.02 in) to determine that there is no leak in the EVAP system.

⇒ | If a leak is detected, use the J 41413-200 to apply smoke to the EVAP system at the filler neck until the leak is located.

3. Start the engine with the J 41413-200 connected to the fuel filler neck.
4. Allow the engine to idle.
5. Use the Purge/Seal function to seal the system with a scan tool.
6. Command the EVAP canister purge solenoid valve to 20 percent.
7. The vacuum/pressure gage on the J 41413-200 and the FTP parameter on the scan tool should both show vacuum.

⇒ | If the vacuum/pressure gage shows vacuum but the FTP parameter does not show vacuum, replace the FTP sensor.

⇒ | If neither the FTP parameter nor the vacuum/pressure gage shows vacuum, repair the restriction in the purge path.

8. Verify that the vacuum increases to the abort limit on the scan tool or more than 3.2 volts, and the value is closely similar between the scan tool and the vacuum/pressure gage on the J 41413-200 .

⇒ | If the values are not similar or the voltage did not reach 3.2 volts, replace the FTP sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Fuel Tank Pressure Sensor Replacement

• | Control Module References for engine control module (ECM) replacement, setup, and programming