OBD codes / P0328
P0328
ModerateKnock Sensor 1 Circuit High (Bank 1)
P0328 is generally safe to drive with — when the computer can't trust the knock signal it protects the engine by running conservative timing, at the cost of a little power and economy. Fix it at your convenience, but move faster if you actually hear pinging or rattling under acceleration.
What this code means
The knock sensor "listens" for the rattle of detonation (pinging) so the computer can pull ignition timing before it damages the engine. P0328 means the signal from knock sensor 1 on Bank 1 is reading HIGHER than the expected range — as opposed to P0327, which is the same circuit reading low. Common causes are a failing sensor, a wiring fault or short pulling the signal high, a loose or over-torqued sensor (mounting torque matters, since the sensor reads vibration through its body), or genuine excessive engine noise from something mechanical. With an untrustworthy knock signal the computer plays it safe and runs conservative ignition timing, which you may notice as mild sluggishness and slightly worse fuel economy — the engine is protected, just detuned.
Symptoms you might notice
- Check-engine light, often with no obvious change
- Slightly sluggish acceleration
- Minor drop in fuel economy
- Pinging under load in some cases
What it costs to fix
Typical range: $150–$600 · about ~0.5–3 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Knock sensor | $40–$200 | ~0.5–3 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
The sensor is cheap; labor varies wildly by engine. On many V-type engines the knock sensors sit in the valley under the intake manifold, so most of the bill is removing the intake to reach them. On engines with the sensor on the block's side, it's a quick job.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0328 for my exact vehicle →
Frequently asked
What does 'circuit high' mean on P0328?
The voltage or signal level from the sensor is above the range the computer expects — the mirror image of P0327 (circuit low). It usually points to the sensor itself, a wiring short pulling the signal high, or a mounting problem, since knock sensors read vibration through their body and are sensitive to torque.
Can I drive with P0328?
Yes, generally. The computer defaults to conservative ignition timing when it loses a trustworthy knock signal, so the engine is protected — just slightly less responsive and efficient. Address it sooner if you hear pinging under load.
Why is a cheap sensor sometimes an expensive repair?
On many V6 and V8 engines the knock sensors are mounted in the valley beneath the intake manifold, so the intake has to come off to reach them — that labor is most of the cost. On engines with an accessible block-mounted sensor, it's an inexpensive job.
Could P0328 mean my engine is actually knocking?
It's possible — a persistently high signal can reflect real mechanical noise the sensor is picking up, not just an electrical fault. If the code comes with audible rattling, ticking, or pinging, have the engine listened to before simply replacing the sensor.
Seeing P0328 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0328 for my vehicleSymptoms that trigger P0328
Drivers who get this code often notice one of these — each has its own likely-causes and cost guide:
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0328 from your phone — see our honest guide to the best OBD2 Bluetooth adapters.
Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.