P0441 - Evaporative Emission System (EVAP) Incorrect Purge Flow
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Evaporative Emission System (EVAP) Incorrect Purge Flow (P0441). The reported signal is electrically valid but disagrees with other operating parameters (RPM, load, or other sensors).
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Evaporative Emission System (EVAP) Incorrect Purge Flow – Coil Resistance | Resistance (Ω) | 3 - 30 Ω (typical) | Connector disconnected at 20°C |
| Evaporative Emission System (EVAP) Incorrect Purge Flow – Duty Cycle | PWM (%) | 5 - 95 % (modulates with target) | Engine running, actuator in control |
| Evaporative Emission System (EVAP) Incorrect Purge Flow – Supply Voltage | Voltage (V) | 11.8 - 14.4 V | Ignition ON at connector |
Connector disconnected at 20°C
Engine running, actuator in control
Ignition ON at connector
Oscilloscope Waveform Analysis
2 ms/div, 20 V/divPossible Causes
Evaporative Emission System (EVAP) Incorrect Purge Flow is electrically operational but performing outside calibrated tolerance
Chafed or pinched wiring harness along the signal path to Evaporative Emission System (EVAP) Incorrect Purge Flow
Internal mechanical wear or carbon deposits inside Evaporative Emission System (EVAP) Incorrect Purge Flow
Defective internal output driver or reference circuit in the control module for Evaporative Emission System (EVAP) Incorrect Purge Flow
Symptoms
4
Recommended Solution
Log component live data across varying load points and verify plausibility against engine target model.
Verify loaded supply voltage and harness terminal pins at Evaporative Emission System (EVAP) Incorrect Purge Flow.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Evaporative Emission System (EVAP) Incorrect Purge Flow.
Check supply and the low-side driver at the ECM connector. Replace the actuator or repair the circuit based on the readings.
Mechanic's Tip
Use the scan-tool output test with the scope on the control side at the same time. If duty changes but the actuator does not move, the valve is stuck — not the electrical fault you were chasing.