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Home >> Chevrolet >> 2005 >> Classic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTC P0301-P2401) >> Diagnostic Information & Procedures >> DTC P0455 >> Test Description
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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This test verifies that the EVAP canister purge solenoid valve is electrically functional.
  2. 4:  This test verifies that the EVAP canister vent solenoid valve is electrically functional.
  3. 10:  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.
  4. 12:  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.
DTC P0455

Step Action Values Yes No
Schematic Reference: Engine Controls Schematics or Evaporative Emissions (EVAP) Hose Routing Diagram
Connector End View Reference: Powertrain Control Module (PCM) 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
  1. Inspect the Evaporative Emission (EVAP) System for the following conditions:
    • A loose, missing, or damaged service port Schrader valve
    • A loose, incorrect, missing, or damaged fuel fill cap
    • A damaged EVAP canister purge solenoid valve
  2. Raise the vehicle on a hoist. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Inspect the EVAP system for the following conditions:
    • Any disconnected, improperly routed, kinked, or damaged EVAP pipes and hoses
    • A damaged EVAP canister vent solenoid valve or EVAP canister
Did you find and correct the condition?		 - Go to Step 38  Go to Step 3 
3 
  1. Clear the DTCs with a scan tool.
  2. Command the EVAP canister purge solenoid valve to 50 percent and back to 0 percent with a scan tool.
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 
4  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
  1. Disconnect the EVAP canister purge solenoid valve.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister purge solenoid valve and a known good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.
Does the test lamp illuminate?		 - Go to Step 6  Go to Step 29 
6
  1. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister purge solenoid valve and the control circuit of the EVAP canister purge solenoid valve. Refer to Circuit Testing in Wiring Systems.
  2. Command the EVAP canister purge solenoid valve to 50 percent and then to 0 percent with a scan tool.
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 23  Go to Step 21 
7
  1. Turn ON the ignition, with the engine OFF.
  2. Disconnect the EVAP canister vent solenoid valve.
  3. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister vent solenoid valve and a known good ground. Refer to Troubleshooting with a Test Lamp in Wiring Systems.
Does the test lamp illuminate?		 - Go to Step 8  Go to Step 30 
8
  1. Connect a test lamp between the ignition 1 voltage circuit of the EVAP canister vent solenoid valve and the control circuit of the EVAP canister vent solenoid valve. Refer to Troubleshooting with a Test Lamp in Wiring Systems.
  2. Command the EVAP canister vent solenoid valve ON with a scan tool.
Does the test lamp illuminate?		 - Go to Step 24  Go to Step 22 
9
    IMPORTANT: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
  1. Turn OFF the ignition.
    2. IMPORTANT: Refer to J 41413-200  Evaporative Emission System Tester (EEST) operation manual for detailed instructions. See Special Tools .
  2. Install the J 41415-40  Fuel Tank Cap Adapter to the fuel fill pipe. See Special Tools .
  3. Use the flow meter on J 41413-200  to determine if there is a leak greater than 0. See Special Tools .51 mm (0.02 in) in the EVAP system.
  4. Compare the flow meter's stable floating indicator position to the red flag.
Is the floating indicator below the red flag?		 - Go to Step 12  Go to Step 10 
10 
    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.
  1. Turn OFF the ignition.
  2. Connect J 41413-200  to the vehicle filler neck. See Special Tools .
  3. Use J 41413-200  to apply smoke to the EVAP system. See Special Tools .
Did you locate and repair a leak source?		 - Go to Step 38  Go to Step 11 
11
  1. Connect the J 41413-200  nitrogen/smoke supply hose to the EVAP service port. See Special Tools .
  2. Continue to introduce smoke at 15 second intervals until the leak source has been located.
Did you locate and repair a leak source?		 - Go to Step 38  Go to Step 12 
12 
  1. Use the remote switch to stop introducing smoke.
  2. Connect J 41413-200  nitrogen/smoke supply hose to the fuel filler neck. See Special Tools .
  3. Command the EVAP canister vent solenoid valve open with a scan tool.
  4. Compare the Fuel Tank Pressure Sensor parameter with a scan tool, to the J 41413-200  pressure/vacuum gage. See Special Tools .
Is the scan tool Fuel Tank Pressure Sensor parameter within the specified value of J 41413-200  pressure/vacuum gage?		 1 in H2O Go to Step 13  Go to Step 25 
13
  1. Seal the EVAP system using the EVAP Purge/Seal function with a scan tool.
  2. Turn the nitrogen/smoke valve on the J 41413-200  control panel to NITROGEN. See Special Tools .
  3. Use the J 41413-200  to pressurize the EVAP system to the first specified value. See Special Tools .
Is the Fuel Tank Pressure Sensor parameter more than the second specified value?		 10 in H2O
5 in H2O		 Go to Step 14  Go to Step 25 
14
  1. Use the remote switch to stop introducing nitrogen into the EVAP system.
  2. Increase the EVAP canister purge solenoid valve to 100 percent.
Is the Fuel Tank Pressure Sensor parameter less than the specified value?		 1 in H2O Go to Step 15  Go to Step 17 
15
  1. Connect the nitrogen/smoke hose to the EVAP service port.
  2. Remove the J 41415-40  . See Special Tools .
  3. Install the fuel fill cap to the fuel fill pipe.
  4. Start the engine.
  5. Allow the engine to idle.
  6. Use the purge/seal function to seal the system with a scan tool.
  7. Command the EVAP canister purge solenoid to 30 percent.
  8. Observe the vacuum/pressure gage on the J 41413-200  and the FTP parameter on the scan tool. See Special Tools .
  9. Allow the vacuum to increase on the gage of the J 41413-200  until it reaches approximately 16 inches H2O or until the vacuum reached the abort limit on a scan tool. See Special Tools .
  10. Use the purge/seal function to seal the system, with a scan tool.
Was the FTP parameter on a scan tool within the specified value of the vacuum/pressure gage on the J 41413-200  ?		 1 in H2O Go to Step 16  Go to Step 25 
16 Did the FTP parameter on a scan tool display more than the specified value? 3.2 V Go to Diagnostic Aids Go to Step 25 
17 Disconnect the EVAP canister 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 28  Go to Step 18 
18 Disconnect the EVAP canister purge pipe from the EVAP purge solenoid valve.
Is the Fuel Tank Pressure Sensor parameter less than the specified value?		 1 in H2O Go to Step 33  Go to Step 19 
19 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 31  Go to Step 20 
20 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 35  Go to Step 32 
21 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 38  Go to Step 27 
22 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 38  Go to Step 27 
23 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 38  Go to Step 33 
24 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 38  Go to Step 34 
25 Test the low reference circuit of the fuel tank pressure (FTP) sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 38  Go to Step 26 
26 Test for an intermittent and for a poor connection at the 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 38  Go to Step 36 
27 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 38  Go to Step 37 
28 Repair the pinched or obstructed EVAP canister purge solenoid valve vacuum source.
Did you complete the repair?		 - Go to Step 38  -
29
  1. Repair the open or short to ground in the ignition 1 voltage circuit of the EVAP canister purge solenoid valve. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse as necessary.
Did you complete the repair?		 - Go to Step 38  -
30
  1. 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.
  2. Replace the fuse as necessary.
Did you complete the repair?		 - Go to Step 38  -
31 Repair the restriction in the EVAP purge pipe.
Did you complete the repair?		 - Go to Step 38  -
32 Repair the restriction in the EVAP vapor pipe.
Did you complete the repair?		 - Go to Step 38  -
33 Replace the EVAP canister purge solenoid valve. Refer to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Replacement .
Did you complete the replacement?		 - Go to Step 38  -
34 Replace the EVAP canister vent solenoid valve. Refer to Evaporative Emission (EVAP) Canister Vent Solenoid Valve Replacement .
Did you complete the replacement?		 - Go to Step 38  -
35 Replace the EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement .
Did you complete the replacement?		 - Go to Step 38  -
36 Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .
Did you complete the replacement?		 - Go to Step 38  -
37 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 38  -
38
IMPORTANT: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
    IMPORTANT: Refer to J 41413-200  Evaporative Emissions System Tester (EEST) operation manual for detailed instructions. See Special Tools .
  1. Use the flow meter on J 41413-200  to determine if there is a leak greater than 0. See Special Tools .51 mm (0.02 in) in the EVAP system.
  2. Compare the flow meter's stable floating indicator position to the red flag.
Is the floating indicator below the red flag?		 - Go to Step 39  Go to Step 10 
39
  1. Observe the J 41413-200  pressure/vacuum gage. See Special Tools .
  2. Increase the EVAP purge solenoid valve to 100 percent.
Does the pressure decrease?		 - Go to Step 40  Go to Step 17 
40 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  pressure/vacuum gage?		 1 in H2O Go to Step 41  Go to Step 25 
41 Observe the Capture Info with a scan tool.
Have any other DTCs not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK
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