Knock Sensor 1 Circuit High Input (Bank 1)
The P0328 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the knock sensor (Bank 1) that is higher than the expected range. This typically points to a wiring issue, such as a short to voltage or a faulty sensor. The knock sensor detects engine vibrations caused by detonation (knock) and sends a signal to the ECM to adjust ignition timing. A high input can cause the ECM to retard timing excessively, reducing performance and fuel economy.
01. Most Common Causes
- Faulty knock sensor
- Short to voltage in knock sensor circuit
- Damaged wiring or connector
- Corroded or loose connections
- ECM issue (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Reduced engine power and acceleration
- Poor fuel economy
- Engine knocking or pinging noise
- Possible rough idle
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect knock sensor wiring and connector for damage, corrosion, or shorts.
Step 3: Test knock sensor resistance and voltage with a multimeter (specs vary by vehicle).
Step 4: Check for a short to voltage by backprobing the sensor signal wire with ignition on.
Step 5: If wiring is intact, replace the knock sensor and clear codes.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances. The ECM may retard timing excessively, leading to reduced power, poor fuel economy, and potential engine damage if knocking persists.
How much does it cost to fix?▼
The cost typically ranges from $150 to $400, including parts (knock sensor $50-$150) and labor (1-2 hours).