P0327
Knock Sensor 1 Circuit Low Input (Bank 1)
The knock sensor signal voltage is below the expected range. Usually points to a piezoelectric sensor that has lost its output, or a short to ground in the signal line.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Check engine light on
- Power loss from defensive spark retard
- Increased fuel consumption
- Possible audible pinging under load
Common causes
Ordered by how often each turns out to be the cause.
- Knock sensor failedCommon
- Signal wire shorted to groundPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Knock Sensor
- Knock Sensor Wiring
P0327 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.