All codes
Knock Sensor 1 Circuit Low Input Bank 1
Understand the P0327 low-input knock sensor code on Bank 1 and how it affects timing and performance.
What you may notice
Symptoms
- 01Check engine light on
- 02Reduced power
- 03Slightly worse fuel economy
- 04Possible pinging under load
- 05No obvious symptoms in mild cases
Where to look first
Common causes
- 01Faulty knock sensor
- 02Open or high resistance in the signal circuit
- 03Corroded or loose connector
- 04Damaged wiring near the engine block
Step by step
What to check and repair
- 01Inspect the knock sensor connector and wiring
- 02Measure knock sensor circuit resistance
- 03Check for a loose or corroded ground
- 04Replace the knock sensor if out of spec
What Does P0327 Mean?
The P0327 code indicates the knock sensor signal on Bank 1 is lower than expected. The knock sensor detects detonation so the ECM can retard timing to protect the engine; a low signal means that protection may be compromised.
Why It Hurts Performance
With an unreliable knock signal, the ECM often pulls timing as a safety default, which can reduce power and fuel economy even though the engine is not actually knocking.
How AI4Car Helps
AI4Car lets you watch timing and knock-related data, helping confirm whether the ECM is defaulting to conservative timing because of the sensor fault.