Diagnostic Aids

WARNING: This page is about a different variant/trim than selected.

When using the J 41413-200 Evaporative Emission System Tester (EEST) to apply pressure, you can regulate the amount of pressure by activating the remote switch ON and OFF. See Special Tools . While observing pressure in the EVAP system, using a scan tool, DO NOT use more than 5 inches H2O. More than 5 inches H2O applied to the EVAP system can cause the canister vent solenoid valve to temporarily remain in the closed position, which could lead to misdiagnosis in this procedure.
An intermittent condition could be caused by a damaged EVAP vent housing, a temporary blockage at the EVAP canister vent solenoid valve inlet, or a pinched vent hose. A blockage in the vent system will also cause a poor fuel fill problem.
For intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .
An EVAP canister, vent house, or vent solenoid valve that has restricted flow may cause this DTC to set. Using the purge solenoid valve command with a scan tool will allow vacuum to be applied to the system instead of pressure. With the EVAP canister vent solenoid valve open and the EVAP canister purge solenoid valve commanded to 100 percent, vacuum should not increase to more than 9 inches H2O.

DTC P0446

Step	Action	Values	Yes	No
Schematic Reference: Evaporative Emissions Hose Routing Diagram
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Inspect the evaporative emission (EVAP) system for the following conditions: A damaged EVAP canister vent solenoid valve A pinched EVAP vent hose A damaged EVAP canister-Refer to Evaporative Emission Canister Replacement (Long Wheel Base) or Evaporative Emission Canister Replacement (Short Wheel Base) . Did you find and correct the condition?	-	Go to Step 13	Go to Step 3
3	Turn OFF the ignition. Disconnect the EVAP purge pipe from the EVAP canister purge solenoid valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Turn ON the ignition, with the engine OFF. Is the fuel tank pressure sensor parameter within the specified range?	-1 to +1 in H2O	Go to Step 4	Go to Step 8
4	IMPORTANT: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results. Turn OFF the ignition. Connect the EVAP purge pipe. Connect the J 41413-200 Evaporative Emissions System Tester (EEST) power supply clips to a known good 12-volt source. See Special Tools . Install the GE-41415-50 Fuel Tank Cap Adapter to the fuel fill pipe. See Special Tools . Connect the fuel fill cap to the GE-41415-50 . See Special Tools . Connect the J 41413-200 nitrogen/smoke supply hose to the GE-41415-50 . See Special Tools . Turn ON the ignition, with the engine OFF. Command the EVAP canister purge solenoid valve closed with a scan tool. Turn the nitrogen/smoke valve on the J 41413-200 control panel to NITROGEN. See Special Tools . Use the remote switch to pressurize the EVAP system to the first specified value. Observe the fuel tank pressure sensor in H2O with a scan tool. Command the EVAP canister purge solenoid valve open with a scan tool. Is the fuel tank pressure sensor parameter less than the second specified value?	5 in H2O 1 in H2O	Go to Diagnostic Aids	Go to Step 5
5	Disconnect the EVAP vent hose from the EVAP vent solenoid valve. Is the fuel tank pressure sensor parameter less than the specified value?	1 in H2O	Go to Step 11	Go to Step 6
6	Disconnect the EVAP vent hose from the EVAP canister. Is the fuel tank pressure sensor parameter less than the specified value?	1 in H2O	Go to Step 7	Go to Step 12
7	Repair the pinched or restricted EVAP vent hose. Did you complete the repair?	-	Go to Step 13	-
8	Test for poor connections at the harness connector of 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 13	Go to Step 9
9	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 13	Go to Step 10
10	Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement?	-	Go to Step 13	-
11	Replace the EVAP canister vent solenoid valve. Did you complete the replacement?	-	Go to Step 13	-
12	Replace the EVAP canister. Refer to Evaporative Emission Canister Replacement (Long Wheel Base) or Evaporative Emission Canister Replacement (Short Wheel Base) . Did you complete the replacement?	-	Go to Step 13	-
13	Turn OFF the ignition. Disconnect the EVAP purge pipe from the EVAP canister purge solenoid valve. Turn ON the ignition, with the engine OFF. Is the fuel tank pressure sensor parameter within the specified range?	-1 to +1 in H2O	Go to Step 14	Go to Step 2
14	IMPORTANT: DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results. Turn OFF the ignition. Reconnect all disconnected components. Connect the J 41413-200 to the fuel fill pipe. See Special Tools . Turn ON the ignition, with the engine OFF Command the EVAP canister vent solenoid valve closed with a scan tool. Turn the nitrogen/smoke valve on the J 41413-200 control panel to NITROGEN. See Special Tools . Use the remote switch to pressurize the EVAP system to the first specified value. Observe the fuel tank pressure sensor in H2O with a scan tool. Command the EVAP canister vent solenoid valve open with a scan tool. Observe the fuel tank pressure sensor in H2O with a scan tool. Is the fuel tank pressure sensor parameter less than the second specified value?	5 in H2O 1 in H2O	Go to Step 15	Go to Step 2
15	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