P0328: Knock Sensor 1 Circuit High (Bank 1 or Single Sensor)
Key takeaways
- P0328 means the signal from knock sensor 1, on bank 1 or the only knock sensor, is above what the engine computer expects.
- It is usually safe to drive, but the computer pulls ignition timing as a precaution, so expect a little less power and fuel economy.
- A wire shorted to voltage, a failed sensor, or loud mechanical noise from the engine can all push the signal high.
- An accessible sensor typically costs $150 to $400 installed; a sensor under the intake manifold on many V6 and V8 engines runs about $400 to $900.
- Kia issued an engine computer software upgrade for P0328 on the 2010–2011 Soul 1.6L, so ask for a bulletin check before buying a sensor.
What P0328 means
The sensor that listens for engine knock on bank 1 is sending a signal that’s stronger than the computer thinks is possible. Scanners call it Knock Sensor 1 Circuit High (Bank 1 or Single Sensor); newer tools may say “Knock/Combustion Vibration Sensor 1 Circuit High.” A knock sensor bolts to the engine block and turns vibration from early detonation (knock or ping) into a small voltage, and the computer pulls ignition timing back when it sees knock. When the signal sits above the expected range, the computer sets P0328. That usually means the circuit is shorted to a voltage source, the sensor has failed, or the engine is making enough mechanical noise to swamp it.
Sensor 1 is on bank 1, the side of a V6 or V8 with cylinder 1, or it’s the only knock sensor on engines that have one.
Is it safe to drive?
Yes, in most cases, and gently. The computer runs conservative, retarded ignition timing when it can’t trust the knock signal, so the engine stays protected but a little slower and thirstier. Use the octane your owner’s manual specifies and skip towing and long full-throttle climbs until it’s fixed.
What changes the answer: a deep knocking or rattling from inside the engine, pinging when you accelerate, or a flashing check engine light. A high knock signal plus a noise you can hear may be real engine trouble, not a sensor fault, so ease off and get it checked soon. See can I drive with the check engine light on.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Wiring shorted to voltage, chafed harness or a corroded connector | Inspect the harness and plug; check the signal wire for voltage it shouldn’t have | $100–$250 |
| Engine software needing an update | A bulletin covers your make, model and year | $100–$200, or free under warranty |
| Failed knock sensor, easy to reach (most four-cylinders) | Sensor output out of spec with good wiring | $150–$400 |
| Failed knock sensor under the intake manifold (many V6 and V8 engines) | Same tests, done at the connector; the sensor itself needs the intake removed | $400–$900 |
| Loud mechanical noise (loose heat shield or bracket, or an internal engine knock) | Listen with a stethoscope; check for rattles near the sensor and for internal knock | Varies; an internal knock is a separate, bigger repair |
What to check first
- Listen to the engine. A clean-running, quiet engine points to wiring or the sensor; a rattle or knock you can hear needs chasing first.
- Inspect the connector and harness. Look for chafing against brackets, oil soaking and rodent damage. Found at the harness, it may be a $100–$250 job.
- Ask for a bulletin check. Kia has an engine computer software upgrade for P0328 on the 2010–2011 Soul 1.6L. Subaru issued bulletins on 2011–2017 models announcing a redesigned, more durable knock sensor that list P0328.
- Test the sensor at the connector before anyone pulls the intake. If the sensor is buried, ask whether replacing both sensors and the harness while it’s open makes sense.
- Clear it and drive after a wiring repair or software update; a circuit fault usually resets within a drive or two if it isn’t fixed.
6 complaints filed with NHTSA mention P0328, and 3 of those are 2016 Honda Pilots. That’s a small number and an owner report, not a confirmed cause.
What it costs
The cheap outcome is a wiring or connector repair at $100–$250, or a software update at $100–$200. The common outcome on an engine with an accessible sensor is a new knock sensor at $150–$400. The expensive outcome is a sensor under the intake manifold on a V6 or V8 at about $400–$900, almost all of it labor. Paying for an hour of diagnosis first, usually $100–$180, saves money, because testing at the connector tells you whether the intake needs to come off at all.
Related codes
P0328 is one of the knock sensor 1 family: P0325 (circuit), P0326 (range or performance) and P0327 (circuit low). On V engines it can show up with the bank 2 code P0330. If a misfire code like P0300 appears too, sort the misfire out first. For what a steady light means, see check engine light on.
What owners report to NHTSA
6 complaints filed with NHTSA mention P0328, 6 of them since 2015, across 4 different models. The component owners most often filed it under: electrical system.
Most-reported models
| Vehicle | Complaints | Model years reported |
|---|---|---|
| HONDA PILOT | 3 | 2016 |
Manufacturer service bulletins that name P0328
4 technical service bulletins and manufacturer communications filed with NHTSA mention P0328, from 2 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- SUBARU FORESTER (2014, 2015, 2016, 2017), bulletin 10140468: 2.0L Turbor Models only. This Service Information Bulletin announces design changes to the engine?s knock sensor which will help improve vehicle assembly line efficiency and increase durability. In some cases, the Check …
- SUBARU B9 TRIBECA (2012, 2013, 2014, 2015), bulletin 10153187: This Service Information Bulletin announces design changes to the engine?s knock sensor which will help improve vehicle assembly line efficiency and increase durability. In some cases, the Check Engine light may illumina…
- KIA SOUL (2010, 2011), bulletin 10090741: TSB: ECM UPGRADE - KNOCK IMPROVEMENT DTC P0328 - THIS BULLETIN PROVIDES INFORMATION RELATED TO THE ECM SOFTWARE UPGRADE FOR SOME 2010-2011MY SOUL (AM) 1.6L VEHICLES WHICH MAY EXPERIENCE A MALFUNCTION INDICATOR LAMP (MIL)…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Can I drive with P0328?
Usually, yes. The computer can't trust the knock signal, so it retards ignition timing to stay safe, and you lose a little power and mileage. Use the fuel grade your owner's manual calls for, avoid heavy towing and full-throttle runs, and get it checked if you hear pinging or a deeper knock under load.
Can engine noise cause P0328?
It can. A knock sensor hears all vibration, not just detonation. A loose heat shield or bracket near the sensor, or a real mechanical knock inside the engine, can push the signal high. If the engine sounds rough or knocks at idle, have that looked at before blaming the sensor.
What is the difference between P0327 and P0328?
Both are knock sensor 1 circuit codes. P0327 means the signal is too low, which points to an open wire or a weak or loose sensor. P0328 means it's too high, which points to a wire shorted to voltage, a failed sensor, excessive engine noise or software.
Should I replace both knock sensors?
If both are under the intake manifold, many shops recommend it, because the labor to reach them is the same and the other sensor is often just as old. If only one is accessible, replace the one the tests point to.