What P0468 means
P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 4, places it in the auxiliary emission controls subsystem; the last two digits identify the specific fault.
Some vehicles use a purge flow sensor to confirm vapour is actually moving from the canister to the engine when the purge valve opens.
What “Circuit High” means here
"High" means the signal or control voltage rose above the maximum the module expects. On a three-wire sensor fed by a 5 V reference, typical causes are a signal wire shorted to the reference or to battery voltage, an open sensor ground, or a failed sensor.
What you may notice
Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0468:
- Usually none
- Purge flow codes stored alongside
Where to start diagnosing P0468
- Check the sensor connector and wiring.
- Confirm the purge valve operates.
- Check for blocked purge lines.
Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.
Live data to watch
These standard OBD2 values relate to P0468. Support varies by vehicle; a value your car does not report will simply be missing.
| Value | What to look for |
|---|---|
| Commanded evaporative purge (PID 0x2E) | Context for the flow reading. |
Related codes
Codes from the same EVAP purge flow sensor family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.
Further reading
Frequently Asked Questions
What does P0468 mean?
P0468 is the generic SAE J2012 code for "EVAP Purge Flow Sensor Circuit High". In plain terms, it means the engine computer has detected a "circuit high" fault on the EVAP purge flow sensor.
Can I keep driving with P0468?
Drivable.
What should I check first for P0468?
Check the sensor connector and wiring.
Definition source: SAE J2012 / ISO 15031-6 generic DTC definitions. This is the generic meaning that applies across makes; a manufacturer can define a code more narrowly or add its own sub-codes, so confirm against the service information for your vehicle before replacing parts. Written by the OBDAssistant engineering team — see our editorial policy.