What Does P0468 Mean?
The purge flow sensor circuit is reading a voltage above the maximum expected threshold, indicating an open circuit in the sensor wiring or a failed sensor producing an abnormally high signal. On some vehicles, this code relates to the EVAP purge control valve circuit reading low. The ECM cannot accurately measure purge flow, and the EVAP system is not properly controlled.
Common Causes
35%
Open circuit in the purge flow sensor signal or ground wire
30%
Failed purge flow sensor with open internal element
15%
Disconnected purge flow sensor connector
12%
Corroded or backed-out pins at the sensor connector
8%
ECM sensor input circuit fault
Diagnostic Steps
1
Verify the purge flow sensor connector is fully seated and locked. Disconnect and reconnect it firmly, then clear codes and retest.
2
Measure the purge flow sensor signal voltage with the key on, engine off. A reading at or near 5V (reference voltage) with the engine running indicates an open sensor or open signal wire.
3
With the sensor disconnected, check continuity on the signal wire from the sensor connector to the ECM connector. Also check the ground wire. Any open circuit must be repaired.
4
Measure the purge flow sensor resistance between its pins (consult manufacturer specs). An OL reading on the sensing element confirms internal sensor failure.
5
Inspect the entire sensor wiring path for breaks, especially near exhaust heat sources, sharp edges, or areas subject to road debris.
Estimated Repair Cost
$100 - $350
Parts + labor, varies by vehicle and location
The purge flow sensor circuit is reading a voltage above the maximum expected threshold, indicating an open circuit in the sensor wiring or a failed sensor producing an abnormally high signal. On some vehicles, this code relates to the EVAP purge control valve circuit reading low. The ECM cannot acc...
The most common cause of P0468 (Evaporative Emission System Purge Control Valve Circuit Low / Purge Flow Sensor Circuit High Input) is: Open circuit in the purge flow sensor signal or ground wire
Typical repair costs for P0468 range from $100 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive with no drivability impact. The EVAP system purge monitoring is disabled. Will fail emissions testing. No mechanical risk to the vehicle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0468 to identify the root cause.
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Quick Info
Category
Powertrain
System
EVAP / Emissions Control
Difficulty
Type
Generic (SAE)
Recommended Tools
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