P0328 means Knock Sensor 1 Circuit High (Bank 1 or Single Sensor). The knock sensor 1 signal voltage is higher than expected. 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 P0328 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.
P0328 symptoms
- Check engine light
- Reduced power as the computer retards timing
- Possible pinging if timing control is affected
Common causes of P0328
- Wiring shorted to voltage
- Failed sensor
- Corroded or water-filled connector
- Very loud real engine noise
How to diagnose P0328
- Inspect the wiring for shorts and the connector for corrosion
- Check the sensor and circuit with a meter
- Listen for real knocking or mechanical noise
Can you drive with P0328?
Usually yes, gently.
P0328 tips
Water or corrosion in the connector can set a high-circuit code. On engines where the sensors sit under the intake, coolant leaks into the valley are a known cause.
Will P0328 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 P0328 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) |
| P0326 | Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor) |
| P0327 | Knock Sensor 1 Circuit Low (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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