P0448

DTC P0448: Evaporative Emission Control System Vent Control Circuit Shorted

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

1) With ignition switch turned OFF, connect scan tool to DLC.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it at idle speed (600 rpm or more) for 1 minute.
4) Check DTC and pending DTC.

DTC Troubleshooting

WARNING:

In order to reduce risk of fire and personal injury, this work must be performed in a well ventilated area and away from any open flames such as gas hot water.

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. Check EVAP canister vent valve power supply circuit.

Disconnect connector from ECM with ignition switch turned OFF.
Disconnect connector from EVAP canister vent valve.
Turn ON ignition switch, measure voltage between vehicle body ground and "G04-7" terminal in ECM harness connector.

Is it voltage 0 V?
YES
Go to Step 3.
NO
"BLK/RED" wire shorted to power supply circuit and faulty ECM.

3. Check EVAP canister vent control valve.

Check EVAP canister vent control valve referring to EVAP Canister Vent Valve Inspection EVAP Canister Vent Valve Inspection.

Is it good condition?
YES
Go to Step 4.
NO
Faulty EVAP canister vent control valve and ECM.

4. Check EVAP canister vent control circuit.

With ignition switch turned OFF, measure resistance between "G04-8" (or "G04-23") terminal wire and "G04-7" terminal in ECM harness connector.

Is resistance above 30 ohms at 20 °C, 68 °F?
YES
Faulty ECM, substitute a known-good ECM and recheck.
NO
Shorted circuit between "BLK/RED" and "BLU/WHT" wire and faulty ECM.