11-09-2009, 09:46 PM
True Car Nut
Join Date: Sep 2008
Location: Arlington, WA
EVAP VENT sol control circuit
Output driver modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the devices which the PCM is commanding on. DTC P0449 indicates an improper voltage level has been detected on the output circuit, which controls the EVAP canister vent valve solenoid.
- The PCM will illuminate the malfunction indicator lamp (MIL) on the second consecutive trip, which the diagnostics test has been run and failed.
- The PCM will store the conditions which were present when the DTC set as Freeze Frame and Failure Records Data.
Check for the following conditions:
- An improper voltage level has been detected on the output circuit, which controls the EVAP canister vent solenoid valve.
- The above conditions are present for at least 30 seconds.
- A faulty connection at the PCM – inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections.
- Inspect the wiring harness for damage. If the harness appears OK, then disconnect the PCM. Turn the ignition on and observe a DMM connected between the EVAP canister purge valve control circuit and ground at the PCM harness connector while moving the connectors and wiring harnesses related to the EVAP canister purge valve. A Change in voltage will indicate the location of the malfunction.
- Listen for an audible click at the vent solenoid valve operates.
- Test for voltage at the feed side of the solenoid. Repair if necessary.
- Verify the PCM is supplying a ground to the solenoid.
- Test if a ground is constantly being applied to the solenoid.
- Solutions may include replacing the solenoid, repairing wiring to the control or feed circuits or replacing a faulty PCM.