What it means
Knock sensor 2 (bank 2) reports a signal level below the diagnostic threshold. The sensor is a piezo element bolted to the engine block; output should be a small AC voltage on each combustion event. A cold or open sensor reads 0 V; a loose mounting bolt damps the signal. Without knock detection, the ECM retards spark globally as a safety measure — fuel economy and power suffer.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Knock sensor 2 on bank 2 detects engine-block vibration and sends a small changing signal to the controller during combustion. P0332 sets when that circuit's signal is below the controller's threshold, which can result from a grounded signal wire, poor connector contact, or a failed sensor; the controller may retard spark because it cannot reliably assess knock.
Common causes
Most likely first.
- Knock sensor failed
- Signal wire shorted to ground
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Power loss from defensive spark retard
- Increased fuel consumption
- Possible audible pinging under load
How to diagnose it
- Check freeze-frame data and related codes, then observe live knock-sensor data to confirm the bank 2 signal is low under the conditions that set the code.
- Inspect knock sensor 2's connector and harness for corrosion, loose terminals, pin damage, or a signal wire rubbed through to ground.
- Using the wiring diagram and manufacturer's procedure, test the signal circuit for a short to ground and check connector continuity.
- Test the sensor and its mounting as specified by the manufacturer to determine whether the sensor itself is producing an inadequate signal.
- Repair the confirmed wiring, connector, or sensor fault, then verify that bank 2 knock-sensor data responds normally.
Common fixes
- Repair a signal wire shorted to ground in the bank 2 knock-sensor circuit.
- Clean or repair corroded terminals and restore a secure connector fit.
- Replace knock sensor 2 on bank 2 if it fails the specified test.
- Clear the code and confirm the low-signal condition does not return.
Can I keep driving?
Drive gently and avoid heavy load, high engine speed, and steep climbs because knock detection on bank 2 may be impaired and power or fuel economy may suffer. Stop if you hear sustained pinging or the engine runs poorly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.