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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1472 (Engine Control System - Diagnosis - 4.2L (DTC P0140 To DTC P0506)) >> Diagnosis >> DTC P0455 >> Test Description

Test Description

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

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. 9:  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. 11:  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-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
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 34  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 25 
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 purge solenoid. 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 20  Go to Step 18 
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 26 
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 21  Go to Step 19 
9 
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 the J 41413-200  Evaporative Emissions System Tester (EEST) power supply clips to a known good 12-volt source.
  3. Install the J 41415-40  Fuel Tank Cap Adapter to the fuel fill pipe.
  4. Connect the fuel fill cap to the J 41415-40  .
  5. Connect the J 41413-200  nitrogen/smoke supply hose to the J 41415-40  .
  6. Turn ON the ignition, with the engine OFF.
  7. Command the EVAP canister vent solenoid valve closed with a scan tool.
  8. Turn the nitrogen/smoke valve on the J 41413-200  control panel to SMOKE.
  9. Use the remote switch to introduce smoke into the EVAP system.
  10. Use the J 41413-VLV  EVAP Service Port Vent Fitting to open the EVAP service port.
  11. Remove the J 41413-VLV  once smoke is observed.
  12. Continue to introduce smoke into the EVAP system for an additional 60 seconds.
  13. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT  High Intensity White Light.
  14. 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 34  Go to Step 10 
10
  1. Disconnect the J 41415-40  from the fuel fill pipe.
  2. Install the fuel fill cap to the fuel fill pipe.
  3. Connect the J 41413-200  nitrogen/smoke supply hose to the EVAP service port.
  4. Use the remote switch to introduce smoke into the EVAP system.
  5. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT  .
  6. 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 34  Go to Step 11 
11 
  1. Use the remote switch to stop introducing smoke.
  2. Install the J 41415-40  to the fuel fill pipe.
  3. Connect the J 41413-200  nitrogen/smoke supply hose to the J 41415-40  .
  4. Connect the vehicle fuel fill cap to the J 41415-40  .
  5. Command the EVAP canister vent solenoid valve open with a scan tool.
  6. Compare the Fuel Tank Pressure Sensor parameter with a scan tool, to the J 41413-200  pressure/vacuum gage.
Is the scan tool Fuel Tank Pressure Sensor parameter within the specified value of the J 41413-200  pressure/vacuum gage?		 1 in H2O Go to Step 12  Go to Step 22 
12
  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.
  3. Use the J 41413-200  to pressurize the EVAP system to the first specified value.
Is the Fuel Tank Pressure Sensor parameter more than the second specified value?		 10 in H2O
5 in H2O		 Go to Step 13  Go to Step 22 
13
  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 Diagnostic Aids Go to Step 14 
14 Disconnect the EVAP 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 24  Go to Step 15 
15 Disconnect the EVAP purge pipe 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 29  Go to Step 16 
16 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 27  Go to Step 17 
17 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 31  Go to Step 28 
18 Test the control circuit of the EVAP canister purge solenoid valve for an open or for a short to voltage. Refer to Circuit Testing andWiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 34  Go to Step 23 
19 Test the control circuit of the EVAP canister vent solenoid valve for an open or for a short to voltage. Refer to Circuit Testing andWiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 34  Go to Step 23 
20 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 34  Go to Step 29 
21 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 34  Go to Step 30 
22 Test for an intermittent and for a poor connection at the fuel tank pressure (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 34  Go to Step 32 
23 Test for an intermittent and for a poor connection at the control module. Refer to Testing for Intermittent Conditions and Poor Connections andConnector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 34  Go to Step 33 
24 Repair the pinched or obstructed EVAP canister purge solenoid valve vacuum source.
Did you complete the repair?		 - Go to Step 34  -
25
  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 34  -
26 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. Replace the fuse as necessary.
Did you complete the repair?		 - Go to Step 34  -
27 Repair the restriction in the EVAP purge pipe. Refer to Evaporative Emission (EVAP) System Cleaning .
Did you complete the repair?		 - Go to Step 34  -
28 Repair the restriction in the EVAP vapor pipe.
Did you complete the repair?		 - Go to Step 34  -
29 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 34  -
30 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 34  -
31 Replace the EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement (TrailBlazer EXT, Envoy XL, Envoy XUV) or Evaporative Emission (EVAP) Canister Replacement (TrailBlazer, Envoy, Bravada, Rainier) .
Did you complete the replacement?		 - Go to Step 34  -
32 Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .
Did you complete the replacement?		 - Go to Step 34  -
33 Replace the control module. Refer to Powertrain Control Module (PCM) Replacement .
Did you complete the replacement?		 - Go to Step 34  -
34
IMPORTANT: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
  1. Turn the nitrogen/smoke valve to nitrogen.
  2. Connect the nitrogen/smoke hose to the 0.5 mm (0.20 in) test orifice on the bottom-front of the J 41413-200  .
  3. Use the remote switch to activate the J 41413-200  .
  4. Align the red flag on the flow meter with the floating indicator. Use the remote switch to de-activate the J 41413-200  .
  5. Install the J 41415-40  to the fuel fill pipe.
  6. Remove the nitrogen/smoke hose from the test orifice and install the hose onto the J 41415-40  .
  7. Turn ON the ignition, with the engine OFF.
  8. Command the EVAP canister vent solenoid valve closed with a scan tool.
  9. Use the remote switch to introduce nitrogen and fill the EVAP system until the floating stabilizes.
  10. Compare the flow meter's stable floating indicator position to the red flag.
Is the floating indicator below the red flag?		 5 in H2O Go to Step 35  Go to Step 2 
35 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
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