P0327: Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
Quick Answer
Safe to drive (short-term)
P0327 means the ECU detected a voltage signal from knock sensor 1 (or the single knock sensor on inline-4 engines) that is below the expected range. The knock sensor is a piezo-electric device bolted to the engine block that listens for the high-frequency vibration of detonation. A low input typically points to a failed sensor, damaged wiring, or a poor electrical connection.
- Severity
- Moderate · Electrical
- Estimated repair cost
- From €60 to €700+, varies by vehicle
€60 or €700, depending on your car.
- Repair connector or wiring at knock sensor€60–€190
- Replace knock sensor under intake manifold (V6/V8)€240–€700
A scan shows whether P0327 is really stored on your car, which codes sit next to it and how urgent each one is.
A scan needs a Bluetooth OBD2 adapter (Bluetooth LE on iPhone), about €25-60; the built-in demo runs without one. See which adapter to buy
What does P0327 mean?
P0327 is a electrical-related diagnostic trouble code classified as moderate severity.
What are the symptoms of P0327?
- Check engine light illuminated
- Reduced engine power, especially under acceleration
- Pinging or knocking sound under load
- Reduced fuel economy
- Possible engine hesitation
What causes P0327?
Faulty knock sensor (failed piezo element)
: high
Damaged wiring or chafed harness to the sensor
: medium
Heat-cycle fatigue on aging sensor (typical at 120,000+ km)
: medium
Loose or corroded sensor connector
: medium
Incorrect torque on intake or knock sensor bolts after recent service
: low
Is it safe to drive with P0327?
Generally yes, for short-term driving. You can drive short distances, but the ECU will retard ignition timing as a precaution, reducing power and fuel economy. Sustained driving under load (heavy acceleration, towing, or highway hills) can cause untracked detonation that damages pistons over time. Repair within a few weeks.
How do you diagnose P0327?
- Locate knock sensor 1. On inline-4 engines it is bolted to the engine block, typically on the intake side. On V6 and V8 engines, knock sensors often sit in the valley under the intake manifold, which makes access expensive
- Inspect the connector for corrosion or damage. Disconnect, clean with electrical contact cleaner, and reseat. Clear the code and drive several cycles to see if it returns
- Measure sensor resistance with a multimeter. Depending on design, knock sensors read anywhere from roughly 100 kΩ to several megohms, and some show no continuity at all, so compare with the figure for your engine rather than a generic number. A reading near zero indicates a shorted sensor
- Inspect the wiring from the sensor back to the ECU connector. Look for chafing, rodent damage, or breaks. The wire is a shielded twisted pair on most modern designs
- If the sensor and wiring are good, verify mounting torque. Knock sensors are torque-sensitive (typically 20 to 25 Nm). Loose or over-tight mounting alters the sensor signal and can trigger P0327
How much does P0327 cost to fix?
| Repair | Parts Cost | Labor Cost | Total Estimate | DIY Difficulty |
|---|---|---|---|---|
| Repair connector or wiring at knock sensor | €10–€40 | €50–€150 | €60–€190 | Moderate |
| Replace knock sensor (inline-4, accessible) | €40–€150 | €50–€100 | €90–€250 | Moderate |
| Replace knock sensor under intake manifold (V6/V8) | €40–€200 | €200–€500 | €240–€700 | Professional |
Prices estimated as of October 2026. Costs vary by region, vehicle, and shop.
P0327 on specific vehicles
BMW
BMW 3 Series
2005-2024
On BMW N52 inline-6 engines the two knock sensors bolt to the block underneath the intake manifold, which has to come off to reach them. Because both sensors have aged together, consider replacing both while the manifold is off.
Source: pelicanparts.com
P0327 on Volkswagen
Volkswagen Golf
P0327 on Audi
P0327 on Toyota
Toyota Camry
Related diagnostic codes
Common questions about P0327
- Can I drive with a knock sensor code?
- Short distances yes, but not long-term. The ECU pulls ignition timing as a safety measure when it cannot trust the knock sensor signal, costing you fuel economy and noticeable power. More importantly, the ECU has no way to detect actual detonation. Sustained heavy load can damage pistons over weeks or months.
- Why is the knock sensor so expensive to replace on a V6 or V8?
- On most V6 and V8 engines, knock sensors are mounted in the valley between the cylinder banks, under the intake manifold. The intake must come off to access them. On engines like the Toyota 2GR-FE V6, this is a 3 to 5 hour job with labour around 250 to 400 EUR even though the sensor itself is only 40 to 80 EUR. The sensors are typically replaced as a pair while the intake is off.
- What is the difference between P0327 and P0328?
- Both refer to knock sensor 1 (or the single sensor). P0327 is low input (signal voltage too low) while P0328 is high input (signal voltage too high). Both can come from a failed sensor or a wiring fault, so test the sensor and the wiring rather than assuming one or the other.
- Can a recent intake manifold service cause P0327?
- Yes. If the intake manifold was removed for cleaning, gasket replacement, or fuel injector service, the knock sensor bolts may not have been torqued to the correct spec (typically 20 to 25 Nm). Loose or over-tight mounting changes the sensor's resonance and the ECU can flag it as an out-of-range signal. Ask the shop to recheck torque before replacing the sensor.
Read our detailed guides
Sources
- pelicanparts.com pelicanparts.com/BMW/techarticles/BMW-3-Series-E90/FUEL-Knock_Sensor_Replacement