What Does P0327 Mean?
Knock sensor 1 on Bank 1 is reporting a low voltage signal, below the minimum threshold expected by the PCM. This typically means the sensor is either failing, improperly installed, or has a wiring issue causing signal attenuation. The PCM cannot properly detect engine knock and will apply a default timing retard strategy to protect the engine.
Common Causes
35%
Failed knock sensor with weak or no piezoelectric output
25%
Knock sensor not torqued correctly (usually under-torqued) reducing contact with the engine block
20%
High resistance in the knock sensor wiring causing signal voltage drop
12%
Contaminated or corroded sensor mounting surface dampening vibration transfer
8%
PCM ground issue affecting the knock sensor circuit reference
Diagnostic Steps
1
Monitor the knock sensor 1 PID voltage at idle — it should show a small fluctuating voltage (typically 0.5–2.5V depending on application). A flat or near-zero signal indicates a dead sensor.
2
Remove the knock sensor, clean the mounting boss on the engine block with a wire brush, and reinstall with a new washer to the exact torque specification.
3
Measure the knock sensor circuit wiring resistance from the sensor connector to the PCM connector — total resistance should be under 5 ohms. Higher values indicate a connection problem.
4
Test the sensor itself: measure resistance between the sensor terminals (typical range 50K–600K ohms). If out of range, replace the sensor.
5
Check all engine and PCM grounds for corrosion and tightness. A poor ground reference will cause all sensor readings to be low.
Estimated Repair Cost
$80 - $350
Parts + labor, varies by vehicle and location
Knock sensor 1 on Bank 1 is reporting a low voltage signal, below the minimum threshold expected by the PCM. This typically means the sensor is either failing, improperly installed, or has a wiring issue causing signal attenuation. The PCM cannot properly detect engine knock and will apply a default...
The most common cause of P0327 (Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)) is: Failed knock sensor with weak or no piezoelectric output
Typical repair costs for P0327 range from $80 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
You can drive the vehicle, but the PCM will retard timing defensively, reducing power and efficiency. Avoid high-load driving conditions (towing, mountain passes, heavy acceleration) until the sensor is replaced. Using higher-octane fuel provides an extra margin of safety against undetected knock.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0327 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Ignition / Knock Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
