P0327 means Knock Sensor 1 Circuit Low (Bank 1 or Single Sensor). The signal from knock sensor 1 is lower than expected, usually because of a wiring or connector fault. 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 P0327 means
The engine computer uses the crankshaft position sensor to know engine speed and piston position, and the camshaft sensors to know which stroke each cylinder is on. On engines with variable valve timing, oil-driven cam phasers rotate the camshafts relative to the crankshaft under the control of solenoids. Timing codes come from a sensor that cannot be read, or from a measured cam angle that does not match the commanded one, so oil level and condition, sensor signals and mechanical timing all need checking.
P0327 symptoms
- Check engine light
- Reduced power or fuel economy as timing is retarded as a precaution
- Pinging under load on some vehicles
Common causes of P0327
- Corroded or damaged knock sensor harness
- Failed knock sensor
- Loose sensor (incorrect torque)
How to diagnose P0327
- Inspect the harness and connector
- Measure sensor resistance or output as specified
- Check sensor torque
Can you drive with P0327?
Usually yes, but use the recommended fuel and avoid heavy load until repaired.
P0327 tips
On GM LS-family truck V8s the knock sensors sit in the valley under the intake manifold, and a corroded harness there is a well-known cause of P0327 and P0332; the harness is often replaced along with the sensors because it is reached through the same work.
Will P0327 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 P0327 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) |
| P0332 | Knock Sensor 2 Circuit Low (Bank 2) |
| P0300 | Random/Multiple Cylinder Misfire Detected |
Guides that help
When it is more than a sensor
If a stretched chain has already jumped time and damaged valves, or low oil pressure has worn the engine, a repair can cost more than a replacement; see engine replacement cost and compare engines by code on our engines page.
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