P0326 means Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor). The knock sensor 1 signal is present but outside the range the computer expects for current engine conditions. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0326 means
Most engine sensors receive a 5-volt reference and return a signal between roughly 0 and 5 volts. Codes ending in circuit high or circuit low usually point to an electrical fault: an open circuit, a short or an unplugged connector. Range/performance codes mean a signal is present but disagrees with what the computer expects from the other sensors, which more often points to a dirty sensor, an air leak or a mechanical problem.
P0326 symptoms
- Check engine light
- Reduced power or sluggish acceleration as timing is retarded
- Lower fuel economy
Common causes of P0326
- Damaged knock sensor wiring, often under the intake manifold
- Incorrect sensor torque
- Failed sensor
- Real engine noise from mechanical problems
How to diagnose P0326
- Inspect the harness and connector
- Check sensor torque against specification when accessible
- Rule out real knock or mechanical noise
Can you drive with P0326?
Usually yes, with reduced power.
P0326 tips
Knock sensors are sensitive to mounting torque. If the sensor was recently replaced, check it was tightened to specification.
Will P0326 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0326 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0325 | Knock Sensor 1 Circuit (Bank 1 or Single Sensor) |
| P0327 | Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor) |
| P0328 | Knock Sensor 1 Circuit High (Bank 1 or Single Sensor) |
Guides that help
When it is more than a sensor
Sensor codes are usually fixed with a sensor, a connector, wiring or a leak repair rather than major parts. If testing turns up internal engine trouble instead, see how to tell if an engine is blown and compare engines by code on our engines page.
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