P0327Knock/Combustion Vibration Sensor A Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- The knock sensor is a piezoelectric structure-borne sound sensor bolted to the engine block; the module evaluates its signal per cylinder and retards ignition when it detects knock. Sensor A is the first sensor (bank 1 or a single sensor). With a fault the module retards ignition across the board as protection – noticeable loss of power and higher consumption. P0327 means the diagnostic DC voltage at the sensor input is too low – the signal or return wire is shorted to ground. GM biases each input through a resistor network and sets the code below 8 % of 5 V in 50 of 63 samples, in the first trip; Ford checks actively once every 250 engine cycles on modules with this circuit. Subaru introduced a more durable sensor for this fault.
- What you may notice
- Check engine light on
- Loss of power, sluggish response from ignition retard
- Higher fuel consumption
- Likely causes
- LikelySignal or return wire chafed to ground
- PossibleMoisture or corrosion in connector or sensor
- PossibleSensor faulty internally (series issue on some models)
- RareEngine module internal
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.