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 00: Evaporative Emission (EVAP) System Large Leak

### Circuit/System Description

The engine control module (ECM) tests the evaporative emission (EVAP) system for a large leak. The ECM monitors the fuel tank pressure sensor signal to determine the EVAP system vacuum level. When the conditions for running are met, the ECM commands the EVAP canister purge solenoid valve open and the EVAP canister vent solenoid valve closed. This allows engine vacuum to enter the EVAP system. At a calibrated time, or vacuum level, the ECM commands the EVAP canister purge solenoid closed, sealing the system, and monitors the fuel tank pressure sensor input in order to determine the EVAP system vacuum level. The following table illustrates the relationship between the ON and OFF states, and the open or closed states of the EVAP canister purge solenoid and EVAP canister vent solenoid valves.

Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve
--- | --- | ---
On | Open | Closed/Not Venting
Off | Closed | Open/Venting

### Conditions for Running the DTC

• | DTCs P000A 00, P000B 00, P0010 00, P0013 00, P0016 00, P0017 00, P0030 00, P0031 00, P0032 00, P0111 00, P0112 00, P0113 00, P0114 00, P0117 00, P0118 00, P0119 00, P0121 00, P0122 00, P0123 00, P0130 00, P0130 01, P0132 00, P0133 00, P0134 00, P0135 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0221 00, P0222 00, P0223 00, P0261 00, P0262 00, P0264 00, P0265 00, P0267 00, P0268 00, P0270 00, P0271 00, P0300 00, P0301 00, P0302 00, P0303 00, P0304 00, P0335 00, P0336 00, P0340 00, P0341 00, P0365 00, P0366 00, P0436 00, P0442 00, P0443 00, P0446 00, P0449 00, P0451 00, P0452 00, P0453 00, P0454 00, P0456 00, P0458 00, P0459 00, P0496 00, P0498 00, P0499 00, P0500 00, P0506 00, P0500 007, P0562 00, P0563 00, P0601 00, P0602 00, P0604 00, P0606 00, P0607 00, P061A 00, P0642 00, P0643 00, P2088 00, P2089 00, P2090 00, P2091 00, P2100 00, P2101 00, P2119 00, P2176 00, P2297 00, P2301 00, P2304 00, P2307 00, P2310 00, P2610 00, and P2A00 00 are not set.

• | The engine is running.

• | The ignition voltage is between 10-18 V.

• | The barometric pressure (BARO) is more than 75 kPa (11 PSI).

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

• | The fuel level is between 6-40 L (2-10 gal).

• | The vehicle speed is 0 km/h (0 mph).

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

• | The engine is operating in closed loop fuel control.

• | DTC P0455 00 runs once per cold start within 10 min of start-up.

### 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

DTC P0455 00 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0455 00 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 EN-41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with a high intensity white light. Introducing smoke in 15 s 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 a high intensity white light.

### Reference Information

#### Schematic Reference

• | Engine Controls Schematics

• | LINK (Evaporative Emission Hose Routing Diagram)

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Evaporative Emission Control System Diagnosis

#### 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

EN-41413-200 Evaporative Emissions System Tester (EEST)

CH-48096 EVAP Service Access Port Tool

GE-41415-50 Fuel Tank Cap Adapter

EN-41413-300 EVAP Cap and Plug Kit

J 41413-311 EVAP Plug

EN-41413-VLV EVAP Service Port Vent Fitting

For equivalent regional tools, refer to Special Tools.

### Circuit/System Testing

Note:

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

• | Refer to the EN-41413-200 Evaporative Emissions System Tester (EEST) operation manual for detailed instructions in Alcohol/Contaminants-in-Fuel Diagnosis.

1. Connect the EN-41413-200 Evaporative Emissions System Tester (EEST) nitrogen/smoke hose to the J 41413-311 EVAP Plug brass cone adapter.
2. Disconnect the hose at the fuel cap end of the GE-41415-50 Fuel Tank Cap Adapter . Connect the J 41413-311 EVAP Plug to the disconnected hose on the GE-41415-50 Fuel Tank Cap Adapter .
3. Install the GE-41415-50 Fuel Tank Cap Adapter filler neck end only to the vehicle.
4. Disconnect the harness connector at the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve.
5. Use jumper wires to close the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve.
6. Use the flow meter on the EN-41413-200 Evaporative Emissions System Tester (EEST) , 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 EN-41413-200 Evaporative Emissions System Tester (EEST) 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 gauge on the EN-41413-200 Evaporative Emissions System Tester (EEST) and the B150 Fuel Tank Pressure (FTP) Sensor parameter on the scan tool should both show vacuum.

⇒ | If the vacuum/pressure gauge shows vacuum but the B150 Fuel Tank Pressure (FTP) Sensor parameter does not show vacuum, replace the B150 Fuel Tank Pressure (FTP) Sensor.

⇒ | If neither the B150 Fuel Tank Pressure (FTP) Sensor parameter or the vacuum/pressure gauge shows vacuum, repair the restriction in the purge path.

9. Verify that the vacuum increases to -2 kPa (0.3 PSI), 3.0 V, and the value is similar between the scan tool and the vacuum/pressure gauge on the EN-41413-200 Evaporative Emissions System Tester (EEST) .

⇒ | If the values are not similar or the voltage did not reach -2 kPa (0.3 PSI), 3.0 V, replace the B150 Fuel Tank Pressure (FTP) Sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | LINK (Fuel Tank Pressure Sensor Replacement)

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