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 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 to verify that the EVAP system is able to reach a predetermined vacuum level within a set amount of time.

### Conditions for Running the DTC

• | DTCs P000A, P000B, P0010, P0013, P0016, P0017, P0030, P0031, P0032, P0068, P0072, P0073, P0074, P009A, P0101, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0130, P0131, P0132, P0133, P0134, P0135, P0171, P0172, P0201, P0202, P0203, P0204, P0221, P0222, P0223, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0335, P0336, P0340, P0341, P0365, P0366, P0436, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0456, P0458, P0459, P0496, P0498, P0499, P0500, P0506, P0507, P0562, P0563, P0601, P0602, P0604, P0605, P0606, P0607, P061A, P061B, P061C, P0642, P0643, P1101, P2088, P2089, P2090, P2091, P2100, P2101, P2119, P2176, P2227, P2228, P2229, P2297, P2301, P2304, P2307, P2310, P2610, and P2A00 are not set.

• | The Ignition is ON.

• | The barometric pressure (BARO) is more than 75 kPa.

• | The engine coolant temperature (ECT) is less than 110°C (230°F).

• | The engine has been running between 1-10 minutes.

• | The engine is idling.

• | The fuel level is between 6-40 liters (2-10 gallons).

• | The fuel tank pressure (FTP) is between -3 and +1 kPa (-12 and +4 in H2O).

• | The vehicle speed is 0 kph (0 mph).

• | The intake air temperature (IAT) is between -8 and +70°C (+17 and +158°F).

• | The battery voltage is more than 10 volts.

• | The engine is operating in Closed Loop fuel control.

• | DTC P0455 runs once per drive cycle when the above conditions are met.

### Conditions for Setting the DTC

The EVAP system is not able to achieve or maintain vacuum before purge has reached a calibrated volume.

### Action Taken When the DTC Sets

DTCs P0455 is a Type B DTC.

### Conditions for Clearing the MIL/DTC

DTCs P0455 is a Type B DTC.

### Diagnostic Aids

• | Inspect for a loose, missing, incorrect, or damaged fuel fill cap.

• | Verify that the fuel filler neck sealing surface is not distorted or damaged.

• | To help locate intermittent leaks, use the J 41413-200 (J 41413-100) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with a high intensity white light.

• | 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.

• | 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 using the adapters in the J 41413-300 .

### Reference Information

#### Schematic Reference

• | Engine Controls Schematics

• | Evaporative Emissions Hose Routing Diagram

#### Connector End View Reference

Component Connector End Views

#### Description and Operation Reference

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

• | CH-48096 EVAP Service Access Port Tool

• | GE-41415-50 Fuel Tank Cap Adapter

• | J 41413-200 (J 41413-100) Evaporative Emission System Tester (EEST)

• | J 41413-300 EVAP Cap and Plug Kit

• | J 41413-311 EVAP Plug

• | J 41413-VLV EVAP Port Vent Fitting Tool

### 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 (J 41413-100) operation manual for detailed instructions in Evaporative Emission System Diagnosis.

1. Connect the J 41413-200 (J 41413-100) nitrogen/smoke hose to the J 41413-311 brass cone adapter.
2. 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 .
3. Install the GE-41415-50 filler neck end only to the vehicle.
4. Disconnect the harness connector at the EVAP canister vent solenoid valve.
5. Use jumper wires to close the EVAP canister vent solenoid valve.
6. Use the flow meter on the J 41413-200 (J 41413-100) , calibrated to 0.51 mm (0.020 in) to determine that there is no leak in the EVAP system.

⇒ | If a leak is detected, use the J 41413-200 (J 41413-100) to apply smoke to the EVAP system at the purge tube or the filler neck until the leak is located.

7. Use the hand vacuum pump at the purge tube to create a vacuum on the EVAP system.
8. Engine running, the vacuum/pressure gage on the J 41413-200 (J 41413-100) 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.

9. Verify that the vacuum increases to -2 kPa (-8 in H2O), 3.0 volts, and the value is similar between the scan tool and the vacuum/pressure gage on the J 41413-200 (J 41413-100).

⇒ | If the values are not similar or the voltage did not reach -2 kPa (-8 in H2O), 3.0 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 ECM replacement, setup, and programming