OBD-II Code · Sensors
P0326
Knock Sensor 1 Range/Performance
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 signal out of range.
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
- Pinging
Likely causes
- Failed sensorMost common
- Loose mounting bolt
Read the full diagnostic procedureP0326 means the knock sensor signal is present but its amplitude or frequency profile is outside the expected window - it sees the sensor electricall…
P0326 means the knock sensor signal is present but its amplitude or frequency profile is outside the expected window - it sees the sensor electrically but the noise floor is wrong.
The cheapest-first diagnostic is a controlled tap test
- with the scan tool graphing knock sensor counts or KR (knock retard) live, lightly tap the engine block within 6 inches of the sensor with a small wrench.
- A healthy sensor produces immediate, sharp spikes.
- No response means a dead or detached sensor; constant high noise even at idle means a cracked sensor or a torque problem (most knock sensors require a specific torque, typically 15-22 ft-lb, to couple properly to the block).
- Verify resistance against type: piezo flat-washer about 4-5 megohms, resonant about 90-110 kohm.
- Inspect for any contact between the sensor body and a harness, bracket, or coolant line that would inject mechanical noise.
- Caveat: aftermarket knock sensors frequently have wrong resonant frequency for the PCM calibration and will set P0326 even though they pass a bench test.
Vehicle-specific patterns1999-2007 GM 4.8/5.3/6.0 LS trucks routinely set P0326 from the same under-intake harness corrosion that causes P0325/P0327 - the signal makes it thr…
- 1999-2007GM 4.8/5.3/6.0 LS trucks routinely set P0326 from the same under-intake harness corrosion that causes P0325/P0327 - the signal makes it through but is degraded.
- 2003-2008Honda Accord/CR-V K24 K-series engines set P0326 when the knock sensor cracks internally after long heat cycling.
- 2006-2012Audi/VW 2.0T FSI (BPY, CCTA) sets P0326 from chafed harness on the engine block.
- 2005-2008Subaru Legacy/Outback 2.5L turbo has a TSB for incorrect knock sensor torque from the factory.
Estimated repair$80 to $700.
Look up another code
P0326 — frequently asked
What does a P0326 code mean?
Knock sensor signal out of range.
What causes a P0326 code?
Common causes: Failed sensor; Loose mounting bolt.
What are the symptoms of a P0326 code?
Typical symptoms: Check engine light; Pinging.
Is it safe to drive with a P0326 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 P0326 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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