P0327: Knock sensor 1 circuit low input (Bank 1)
Drive carefully. Get it checked within a week or two.
Can I drive with P0327?
Yes, but drive carefully and get it checked soon. Knock sensor voltage is below threshold; engine retards timing and feels sluggish.
What does P0327 mean?
P0327 stands for Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor).
Symptoms you may notice
- Check engine light steadily illuminated
- Slight hesitation or change in throttle response
- Possible increase in fuel consumption
How much does it cost to fix?
Repair costs for code P0327 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Defective knock sensor
- Corroded wiring plug in engine valley
- Rodent chewing on knock sensor wire harness
- Loose sensor mounting bolt
What to do next
- Inspect the knock sensor sub-harness under the intake manifold for damage.
- Test knock sensor resistance with a digital multimeter.
- Replace the knock sensor and harness.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P0327 indicates low voltage from the knock sensor. On GM trucks, water enters the intake valley and corrodes the knock sensors. Safe to drive, but engine power will feel dampened.