Basically, the EVAP purge control system is designed to allow vacuum in the EVAP system to enter the engine to be burned. The EVAP system is part of the fuel system and is an emissions control system designed to eliminate evaporation of fuel / fumes from entering the atmosphere. What has set your check engine light is this. The computer is not receiving a signal from the purge control circuit. This circuit is what opens and allows the vacuum to enter the engine. Basically, it's like someone has disconnected the wiring. The first thing you need to do is to make sure nothing is disconnected or damaged. I was able to find the information below online to help you go through a test. I hope it helps. NOTE: You will not notice any difference in the performance of the vehicle with this code set. The engine will continue to run normally. However, it will not pass an emissions test.
DTC P0444 - EVAP Purge Control Circuit No Signal
1
Perform EOBD System Check.
Task Done?
Look up Step 2
Look up "On-Board Diagnostic System Check"
2
De-link the evaporative emission (EVAP) canister purge valve connector.
Link up a test light between the EVAP canister purge valve connector terminal 2 and battery positive.
Can you see the test light ON?
Look up Step 3
Look up Step 5
3
Dissociate the ECM connector.
Attach a test light between the ECM connector terminal 65 and ground.
Can you see the test light ON?
Look up Step 4
Look up Step 6
4
Repair the line break in the wire between the EVAP canister purge valve connector 1 and the ECM connector terminal 65.
Clear any Diagnostic Trouble Codes (DTCs) from the ECM.
Perform the diagnostic system check.
5
Repair the line break in the wire between the EVAP canister purge valve connector 2 and the main relay connector terminal 87.
Clear any Diagnostic Trouble Codes (DTCs) from the ECM.
Perform the diagnostic system check.
6
Change the ECM.
Carry out the diagnostic system check.
Task Accomplished?
Look up Step 7
7
1) Unset all DTCs taking a Scan Tool.
2) Start the engine and idle at normal operating temperature.
3) Operate the vehicle within the specified conditions for setting this DTC
Do you see the scan tool confirming that this diagnostic has been operated and the test passed?
Look up Step 8
Look up Step 2
8
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?
Look up Applicable DTC table
Sunday, July 6th, 2014 AT 2:37 PM