DTC Advanced Diagnostics: P0443
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 intake manifold and the EVAP canister. The powertrain control module (PCM) does not turn on the EVAP canister purge valve when the engine coolant temperature is less than a specified value. The 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 PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
5 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [BATTERY]
10.0 V
–
EVAP canister purge valve output duty [EVAP PC DUTY]
2 %
98 %
State of the engine
Running
[ ]: HDS Parameter

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

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
EVAP canister purge valve PCS line open
EVAP canister purge valve PCS line short to ground
EVAP canister purge valve power supply line open
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine. Hold the engine speed [ENGINE SPEED] at 3,000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.

With the HDS
None.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.