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Home >> Cadillac >> 2006 >> Escalade EXT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 4.8L, 5.3L, And 6.0L - DTC P0442 To DTC P2120 >> DTC P0455 >> Test Description

Test Description

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

  1. 4:  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.
  2. 6:  This step verifies proper operation of the FTP sensor.
  3. 7:  A normal operating FTP sensor should increase above 5 inches of H2O and stop between 6-7 inches of H2O.
DTC P0455

Step Action Values Yes No
Schematic Reference: Evaporative Emissions (EVAP) Hose Routing Diagram
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Inspect the evaporative emission (EVAP) system for the following conditions:
    • Loose, missing, or damaged service port Schrader valve
    • 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 .
  3. Inspect the EVAP system for the following conditions:
    • 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 21  Go to Step 3 
3
  1. Turn OFF the ignition.
  2. Connect the J 41413-200  Evaporative Emission System Tester (EEST) power supply clips to a known good 12-volt source. See Special Tools .
  3. Turn the nitrogen/smoke valve to NITROGEN.
  4. Connect the nitrogen/smoke hose to the 0.5 mm (0.2 in) test orifice on the bottom-front of the J 41413-200  . See Special Tools .
  5. Use the remote switch to activate the J 41413-200  . See Special Tools .
  6. Align the red flag on the flow meter with the floating indicator. Use the remote switch to deactivate the J 41413-200  . See Special Tools .
  7. Install the J 41415-40  Fuel Tank Cap Adapter to the fuel fill pipe. See Special Tools .
  8. Install the fuel fill cap to the J 41415-40  . See Special Tools .
  9. Remove the nitrogen/smoke hose from the test orifice and install the hose onto the J 41415-40  . See Special Tools .
  10. Turn ON the ignition, with the engine OFF.
  11. Command the EVAP canister vent solenoid valve CLOSED with a scan tool.
  12. Use the remote switch to introduce nitrogen and fill the EVAP system until the floating indicator stabilizes.
  13. Compare the flow meter's stable floating indicator position to the red flag.
Is the floating indicator below the red flag?		 - Go to Step 6  Go to Step 4 
4 
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  power supply clips to a known good 12-volt source. See Special Tools .
  3. Install the J 41415-40  or GE-41415-50  Fuel Tank Cap Adapter to the fuel fill pipe. See Special Tools .
  4. Connect the J 41413-200  nitrogen/smoke supply hose to the J 41415-40  or GE-41415-50  . See Special Tools .
  5. Turn ON the ignition, with the engine OFF
  6. Command the EVAP canister vent solenoid valve closed with a scan tool.
  7. Turn the nitrogen/smoke valve on the J 41413-200  control panel to SMOKE. See Special Tools .
  8. Use the remote switch to introduce smoke into the EVAP system.
  9. Use the J 41413-VLV  EVAP Service Port Vent Fitting to open the EVAP service port. See Special Tools .
  10. Remove the J 41413-VLV  once smoke is observed. See Special Tools .
  11. Continue to introduce smoke into the EVAP system for an additional 60 seconds.
  12. Inspect the entire EVAP system for exiting smoke with the J 41413-SPT  High Intensity White Light. See Special Tools .
  13. 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 21  Go to Step 5 
5
  1. Disconnect the J 41415-40  or GE-41415-50  from the fuel fill pipe. See Special Tools .
  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. See Special Tools .
  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  . See Special Tools .
  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 21  Go to Step 6 
6 
  1. Use the remote switch to stop introducing smoke.
  2. Install the J 41415-40  or GE-41415-50  to the fuel fill pipe. See Special Tools .
  3. Connect the J 41413-200  nitrogen/smoke supply hose and vehicle fuel fill cap to the J 41415-40  or GE-41415-50  . See Special Tools .
  4. Command the EVAP canister vent solenoid valve open with a scan tool.
  5. Compare the fuel tank pressure sensor parameter with a scan tool to the J 41413-200  pressure/vacuum gage. See Special Tools .
Is the difference between the 2 gages less than the specified value?		 1 in H2O Go to Step 7  Go to Step 14 
7 
  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?		 13 in H2O
5 in H2O		 Go to Step 8  Go to Step 14 
8
  1. Stop introducing nitrogen into the EVAP system with the remote switch.
  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 9  Go to Step 11 
9
  1. Connect the nitrogen/smoke hose to the EVAP service port.
  2. Remove the J 41415-40  or GE-41415-50  . 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 purge solenoid valve 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. Use the purge/seal function to seal the system with a scan tool.
Is the difference between the FTP parameter on a scan tool and the vacuum/pressure gage on the J 41413-200  within the specified value, until the vacuum reached the abort limit on the scan tool? See Special Tools .		 1 in H2O Go to Step 10  Go to Step 14 
10 Did the FTP parameter on a scan tool display more than the specified value? 3.2 V Go to Diagnostic Aids Go to Step 17 
11 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 18  Go to Step 12 
12 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 19  Go to Step 13 
13 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 20  Go to Step 16 
14 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 .
Did you find and correct the condition?		 - Go to Step 21  Go to Step 15 
15 Test the low reference circuit of the FTP sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 21  Go to Step 17 
16 Repair the pinched or obstructed EVAP vapor pipe.
Did you complete the repair?		 - Go to Step 21  -
17 Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement (1500 Series) or Fuel Tank Pressure Sensor Replacement (2500 Series) .
Did you complete the replacement?		 - Go to Step 21  -
18 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 21  -
19 Repair the restriction in the EVAP purge pipe. Refer to Evaporative Emission (EVAP) System Hoses/Pipes Replacement (1500 Series) or Evaporative Emission (EVAP) System Hoses/Pipes Replacement (2500 Series - Front Tank) or Evaporative Emission (EVAP) System Hoses/Pipes Replacement (2500 Series - Intermediate) or Evaporative Emission (EVAP) System Hoses/Pipes Replacement (1500 Series - 5.3L (L59) Engine) .
Did you complete the repair?		 - Go to Step 21  -
20 Replace the EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement (1500 Series) or Evaporative Emission (EVAP) Canister Replacement (2500 Series) or Evaporative Emission (EVAP) Canister Replacement (1500 Series - 5.3L (L59) Engine) .
Did you complete the replacement?		 - Go to Step 21  -
21
IMPORTANT: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results.
  1. Connect the J 41413-200  to the fuel fill pipe. See Special Tools .
  2. Turn the nitrogen/smoke valve to NITROGEN.
  3. Seal the EVAP system using the EVAP Purge/Seal function with a scan tool.
  4. Pressurize the EVAP system to the specified value.
  5. Observe the J 41413-200  pressure/vacuum gage for 5 minutes. See Special Tools .
Does the J 41413-200  pressure/vacuum gage remain constant? See Special Tools .		 5 in H2O Go to Step 22  Go to Step 3 
22 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? See Special Tools .		 1 in H2O Go to Step 23  Go to Step 6 
23
  1. Observe the J 41413-200  pressure/vacuum gage. See Special Tools .
  2. Increase the EVAP canister purge solenoid valve to 100 percent.
Does the pressure decrease?		 - Go to Step 24  Go to Step 11 
24 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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