P0444
P0444-EVAP PURGE SOLENOID CIRCUIT OPEN
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Evaporative Purge Monitor tests the integrity of the hoses/tube between the throttle body/intake and the fuel tank. At key off, the Powertrain Control Module (PCM) monitors the Evaporative System Integrity Monitor (ESIM) Switch. As the fuel and air in the Fuel Tank cools, a vacuum will occur naturally inside the tank. One inch of vacuum will cause the switch to close. If the PCM sees the switch close before the counter reaches a calibrated amount, the monitor passes.
The monitor is a two stage test and runs only after the Evaporative system passes the small leak test. Stage one is non-intrusive. With the engine running, the monitor will first evaluate the delta pressure change of the Fuel Tank Pressure (FTP) Sensor while normal purge control is active. If the monitor does not pass within a calibrated amount of time, then an intrusive monitor will be enabled. The intrusive test runs only if stage one does not pass. This intrusive monitor will ramp in the purge flow to a target amount while evaluating the delta pressure in the entire system. If the delta pressure between purge off and purge on exceeds a calibrated amount, then the monitor will ramp out the purge flow and evaluate the delta pressure between the high flow and the new low flow target. If the delta pressure is less than a calibrated threshold then the monitor will pass.
- When Monitored:
With the ignition on.
- Set Condition:
If the PCM detects an open circuit in the Purge Solenoid or in the circuit, a one trip fault is set and the MIL is illuminated.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
1. Start the engine.
2. Allow the engine to idle.
3. With the scan tool, select View DTCs.
Is the DTC Active or Pending at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. CHECK THE (F343) ASD RELAY OUTPUT CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Ignition on, engine not running.
2. Using a test light connected to ground, back probe the (F343) Fused ASD Relay Output circuit at the Purge Solenoid connector.
Does the test light illuminate brightly.
Yes
- Go To 3
No
- Repair the (F343) Fused ASD Relay Output circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
3. PURGE SOLENOID
1. Turn the ignition off.
2. Disconnect the Purge Solenoid harness connector.
3. Measure the resistance across the terminals of the Purge Solenoid.
Is the resistance between 10.0 and 15.0 Ohms?
Yes
- Go To 4
No
- Replace the Evap Purge Solenoid.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. CHECK THE (K52) PURGE SOLENOID CONTROL CIRCUIT OPEN/HIGH RESISTANCE
1. Disconnect the PCM C2 harness connector.
2. Measure the resistance of the (K52) Purge Solenoid Control circuit between the Purge Solenoid harness connector and the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the (K52) Purge Solenoid Control circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Evap Purge Solenoid Assembly, ESIM switch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related Sensor and the Powertrain Control Module harness connectors.
4. Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.