Diagnostic Aids
WARNING: This page is about a different variant/trim than selected.
- An EVAP canister, vent hose, or vent solenoid valve that has restricted flow may cause this DTC to set. Using 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 7 inches H2O.
- 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 Intermittent Conditions .
DTC P0446
| Step |
Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Evaporative Emissions (EVAP) Hose Routing Diagram and Engine Controls Schematics | ||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Inspect the evaporative emission (EVAP) system for the following conditions:
Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 3 |
| 3 |
|
-1 to +1 in H2O | Go to Step 4 | Go to Step 7 |
| 4 |
IMPORTANT:
DO NOT exceed the specified value in this step. Exceeding the specified value may produce incorrect test results.
|
5 in H2O 1 in H2O |
Go to Diagnostic Aids | Go to Step 5 |
| 5 | Disconnect the EVAP vent hose from the EVAP canister 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 8 | Go to Step 12 |
| 7 | 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
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 13 | Go to Step 9 |
| 8 | Repair the pinched or restricted EVAP vent hose. Did you complete the repair? |
- | Go to Step 13 | - |
| 9 | Test the low reference circuit of the 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 13 | Go to Step 10 |
| 10 | Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement (Malibu Sedan)
. Did you complete the replacement? |
- | Go to Step 13 | - |
| 11 | Replace the EVAP canister vent solenoid valve. Refer to Evaporative Emission (EVAP) Canister Vent Solenoid Valve Replacement (Malibu Sedan)
. Did you complete the replacement? |
- | Go to Step 13 | - |
| 12 | Replace the EVAP canister. Refer to Evaporative Emission (EVAP) Canister Replacement (Malibu Sedan)
. Did you complete the replacement? |
- | Go to Step 13 | - |
| 13 |
|
-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.
|
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 in Vehicle DTC Information | System OK |