DTC P0446: EVAP System Vent Control Circuit Low Input - Forester, IMPREZA, Legacy & Outback 2.5L M/T & Outback Sport
- Perform basic diagnostic procedure. See BASIC DIAGNOSTIC PROCEDURE . Turn ignition on. Using DVOM connected to ground, backprobe ECM connector B134 (35-pin connector) terminal No. 10. See Figure. If voltage is more than 10 volts, go to next step. If voltage is not more than 10 volts, go to step 4.
- Check for poor terminal contact in connectors between ECM and drain valve. Repair as required. If no problems are found, system has returned to normal.
- Turn ignition off. Disconnect drain valve connector and ECM connector B134 (35-pin connector). Using an ohmmeter connected to ground, measure resistance at drain valve connector terminal No. 2. See Figure for Legacy and Outback or Fig 1 for Forester, Impreza and Outback Sport. If resistance is not less than 10 ohms, go to next step. If resistance is less than 10 ohms, locate and repair short to ground in wiring between ECM and drain valve. See WIRING DIAGRAMS article.
- Using an ohmmeter, measure resistance between drain valve connector terminal No. 2 and ECM connector B134 (35-pin connector) terminal No. 10. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, locate and repair open circuit in wiring and check for poor terminal contact in connectors between ECM and drain valve.
- Turn ignition off. Measure drain valve resistance by checking across valve terminals. If resistance is 10-100 ohms, go to next step. If resistance is not 10-100 ohms, replace drain valve.
- Turn ignition off. Remove main relay. Connect battery voltage to main relay terminals No. 1 and No. 2. Using an ohmmeter, measure resistance between main relay terminals No. 3 and No. 5. If resistance is less than 10 ohms, go to next step. If resistance is not less than 10 ohms, replace main relay.
- Turn ignition on. Using DVOM connected to ground, measure voltage at drain valve connector terminal No. 1. If voltage is more than 10 volts, go to next step. If voltage is not more than 10 volts, locate and repair open circuit in wiring and check for poor terminal contact in connectors between main relay and drain valve.
- Check for poor terminal contact at drain valve connector. Repair connector as required. If connector is okay, contact authorized Subaru dealership because probable cause is deterioration of multiple parts. Clear memory and perform verification procedure. See CLEARING DIAGNOSTIC TROUBLE CODES and VERIFICATION PROCEDURE
.
Courtesy of SUBARU OF AMERICA, INC.