OBD-II trouble code
P0467: EVAP Purge Flow Sensor Circuit Low Input
The purge flow signal has fallen below the floor the sensor is capable of producing. The most useful question is whether any other sensor logged a low code at the same time — because this sensor shares its 5-volt reference with several others, and a lost rail takes them all down together.
Quick facts
- System
- Powertrain
- Category
- EVAP System
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $80 – $450
- DIY difficulty
- Intermediate DIY
What does P0467 mean?
A purge flow sensor is fed a regulated reference voltage — five volts on virtually every modern application — and returns a signal somewhere between a fraction of a volt and near that reference, rising as vapour flow increases. The module knows the sensor physically cannot produce less than a certain minimum, typically somewhere around a quarter of a volt, even at zero flow. When the signal sits below that floor for longer than a brief moment, the reading has stopped being a measurement of anything and P0467 is stored.
There are exactly three electrical ways to get there, and separating them is the whole diagnosis. The signal wire can be shorted to ground, which drags it to zero regardless of what the sensor is doing. The signal circuit can be open, which on a design biased toward ground reads as nothing rather than as maximum. Or the reference voltage can be missing, which leaves the sensor unpowered and its output collapsed — the sensor being entirely healthy the whole time.
That third possibility is where P0467 earns a diagnostic habit no other member of this family needs: read every stored code before you touch the sensor. Reference voltage is not generated per sensor. The module produces a small number of regulated five-volt rails and shares each one across several devices, so a purge flow sensor typically sits on the same rail as the MAP sensor, a throttle or pedal position sensor, or an exhaust or fuel pressure sensor. When that rail is shorted to ground or lost at a common splice, every sensor on it reports low at once. A scan tool showing P0467 alongside low codes from two or three unrelated sensors is not describing three broken parts — it is describing one shorted rail, and the fault is almost always a single chafed wire or a flooded connector. Buying a purge flow sensor in that situation fixes nothing and costs a morning.
When P0467 arrives alone, the sensor's own circuit is the reasonable place to start, and its physical location tells you what to look for. On most designs the purge solenoid and its sensor sit on or above the intake manifold, in the hottest area under the bonnet, with the harness running across the top of the engine. Insulation there is heat-cycled thousands of times, goes hard and brittle, and eventually cracks where it rubs against a manifold casting, a bracket edge or a coolant pipe. Since the engine and manifold are grounded metal, a cracked signal wire touching any of it produces a dead short to ground — the textbook cause of a low code. This is a different failure mode from the moisture-driven corrosion that dominates faults on underbody harnesses, and it means the inspection is visual and tactile: run the harness through your fingers looking for hardened, shiny or flattened sections rather than for green corrosion.
The test that settles the sensor's fate takes under a minute. Unplug the connector and, with the key on, measure the reference and ground at the harness side. Five volts present and a good ground means the wiring in is fine, so a signal still reading low with the sensor connected indicts the sensor or the signal wire between it and the module. No reference voltage at the connector means the problem is upstream and the sensor was never in the frame.
As with the rest of this family, the driving impact is negligible — purge affects vapour handling rather than combustion. What accumulates is regulatory: the EVAP monitor cannot complete, so an emissions test fails on readiness, and a purge system out of action lets the charcoal canister keep filling until it starts to smell or, eventually, needs replacing.
Common causes
- Signal wire shorted to ground where heat-hardened insulation has cracked against the intake manifold or a bracket
- Loss of the shared 5-volt reference, which takes down every sensor on that rail simultaneously
- Open circuit in the signal wire on a design biased toward ground, which reads as low rather than high
- Connector at the purge solenoid or flow sensor corroded, water-filled or with a pushed-out terminal
- Failed flow sensing element with its output collapsed to zero
- Harness pinched under a bracket or manifold during earlier intake, coil or spark plug work
- Chafe against a coolant pipe or hard line where the harness crosses the top of the engine
- Module input circuit failure, which is rare and should only be considered once wiring is proven
Symptoms
- Check engine light with P0467 stored, usually with no change in how the vehicle drives
- Purge flow PID reading zero or near zero on a scan tool regardless of commanded purge
- Low codes from other, unrelated sensors stored at the same time, which points at a shared reference rail
- EVAP readiness monitor not completing, producing an emissions test failure on readiness
- Fuel smell around the parked vehicle if the canister has begun to saturate
- Fuel economy and engine power essentially unchanged
Diagnostic steps
- 1.Read every stored code before testing anything. Low codes from several unrelated sensors alongside P0467 indicate a shared 5-volt reference fault, not several failed parts.
- 2.If a reference rail is suspected, find which sensors share it in the wiring diagram and look for the common splice or the one chafed wire feeding them all.
- 3.Confirm from service information that a purge flow sensor is fitted to this exact application, and whether it is standalone or built into the purge solenoid.
- 4.Unplug the sensor connector and, key on, measure the reference voltage and ground at the harness side. Five volts and a good ground proves the supply side is healthy.
- 5.If no reference voltage is present at the connector, work back toward the module rather than testing the sensor at all.
- 6.Run the harness across the top of the engine through your fingers, feeling for hardened, flattened or shiny sections rather than looking for corrosion — heat damage is the dominant mode in this location.
- 7.Check the signal wire for a short to ground with the connector unplugged and the module connector disconnected, so a shorted module input cannot mask the result.
- 8.Inspect the connector body for water, oil and pushed-out or spread terminals, and confirm the latch is fully engaged.
- 9.Ask what recent work has been done in the intake area, since a pinched harness from an unrelated job produces this code exactly.
- 10.Only after the supply, ground and signal wiring are proven should the sensor itself be replaced.
Repair cost
$80 – $450
Wiring is the likeliest outcome and the cheapest: repairing a chafed signal wire or re-terminating a corroded connector usually lands between $80 and $200 including diagnostic time. A shared reference fault is in the same bracket once located, though the locating itself can absorb an hour or more of diagnostic labour because it means tracing a rail across several sensors. A discrete flow sensor is typically $40 to $150 with under an hour to fit, giving a total around $150 to $300. The upper end applies where the sensor is integrated into the purge solenoid assembly and cannot be bought separately, putting the part at $80 to $250 and the total near $300 to $450. If the same shop wants to replace two or three sensors that all reported low together, ask them to check the reference rail first.
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DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.