OBD-II Code · Sensors
P0328
Knock Sensor 1 High Input
Severity
medium
Worth booking. It costs fuel, emissions or comfort until it is fixed.
Can you drive it
Only if running normally
A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety.
Indicative cost (USD)
$150–$500
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Knock sensor voltage high.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Likely causes
- Failed sensorMost common
- Wiring short to power
Read the full diagnostic procedureP0328 is knock sensor 1 circuit high - signal voltage above the upper threshold, meaning the sensor is open-circuit, the harness is open, or there is…
P0328 is knock sensor 1 circuit high - signal voltage above the upper threshold, meaning the sensor is open-circuit, the harness is open, or there is a short to voltage.
Cheapest-first
- unplug the sensor and measure its resistance.
- Piezo about 4-5 megohms, resonant about 90-110 kohm; infinite resistance means an internally open sensor.
- With the sensor unplugged and key on, backprobe the signal wire at the harness side - it should sit at the PCM bias (about 2.5 V on most platforms) or near 5 V depending on calibration.
- A reading pinned at battery voltage means a short to voltage in the harness.
- Reconnect, run the engine, and verify with an AC-coupled scope: a healthy sensor produces 20 mV to several hundred mV AC of combustion noise.
- Caveat: same warning as P0327 - on GM LS trucks the actual fault is almost always under the intake manifold, not the sensor itself, and condemning the sensor first will cost the customer a redo.
Vehicle-specific patterns1999-2007 GM 4.8/5.3/6.0 LS trucks set P0328 from the under-intake harness corrosion creating an open instead of a short; same TSB 02-06-04-037 fix.
- 1999-2007GM 4.8/5.3/6.0 LS trucks set P0328 from the under-intake harness corrosion creating an open instead of a short; same TSB 02-06-04-037 fix.
- 2002-2008Honda Civic/CR-V K20/K24 sets P0328 from a cracked knock sensor connector at the back of the block.
- 2007-2013BMW N52/N54 has knock sensor wiring that chafes against the intake manifold supports.
- 2005-2010Audi A4/A6 2.0T sets P0328 from the rear-bank knock sensor harness pulling apart at the connector.
Estimated repair$80 to $700.
Look up another code
P0328 — frequently asked
What does a P0328 code mean?
Knock sensor voltage high.
What causes a P0328 code?
Common causes: Failed sensor; Wiring short to power.
What are the symptoms of a P0328 code?
Typical symptoms: Check engine light.
Is it safe to drive with a P0328 code?
Only if running normally. A short trip to a shop may be reasonable if the light is steady and the car runs normally. Stop safely for a flashing light, severe shaking, overheating, loss of power, or another urgent warning. The code alone cannot confirm safety. Estimated repair: $150-$500.
How do I diagnose a P0328 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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