Advanced Diagnostics

Advanced Diagnostics

DTC P0443: Evaporative Emission (EVAP) Canister Purge Valve Circuit Malfunction







General Description
The evaporative emission (EVAP) canister purge valve is attached to the vacuum port between the EVAP canister and the intake manifold. The engine control module (ECM)/powertrain control module (PCM) does not turn on the EVAP canister purge valve when the engine coolant temperature is 131 °F (55 °C) or less. The ECM/PCM adjusts the amount of fuel vapor sent to the engine by controlling the EVAP canister purge valve duty cycle. When the return signal does not change according to the EVAP canister purge valve output for a set time, the ECM/PCM detects a malfunction, and a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status







Enable Conditions







Malfunction Threshold
The return signal does not change according to the EVAP canister purge valve output for at least 5 seconds.

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the ECM/PCM memory. If the malfunction recurs during the next (second) drive cycle, the MIL comes on and the DTC and the freeze frame data are stored.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive drive cycles in which the engine conditions are similar to the first time the malfunction was detected. The MIL, the DTC, the Temporary DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.