P0332 Code — Knock Sensor 2 Circuit Low Input (Bank 2) – Causes, Costs & Repair Guide 2026

What Triggers a P0332 Code?

The PCM flags P0332 when the voltage from Knock Sensor 2 on bank 2 falls below the manufacturer’s low‑input threshold. Bank 2 is the side of a V‑engine that houses cylinders 4‑6‑8, or cylinders 4‑5‑6 on an inline‑four. A weak signal usually points to a faulty sensor, damaged wiring, or a problem inside the PCM’s input circuit.

How the Knock Sensor Generates a Signal

A knock sensor is a piezoelectric crystal that creates a voltage when it vibrates from detonation events. The PCM reads this voltage and retards ignition timing to protect pistons. Typical idle voltage for a healthy sensor ranges from 0.5 V to 5 V; values below 0.5 V trigger the low‑input condition.

Note: Exact voltage limits differ by make. Always consult the service manual for the precise range.

Typical Sources of Low‑Input Voltage

Diagnostic Flow Overview

The following sequence moves from the simplest, cheapest checks to the more involved tests. Perform each step before moving to the next.

Step 1 – Visual Scan

1. Disconnect the battery (negative terminal first).
2. Locate the knock sensor on the engine block—usually near the cylinder head on bank 2.
3. Inspect the connector for loose pins, burnt contacts, or water intrusion.

Safety tip: After disconnecting the battery, wait five minutes before touching any wires. The vehicle’s capacitors can retain charge.

Step 2 – Live Data Review

1. Plug an OBD‑II scanner into the diagnostic port.
2. Select the “Knock Sensor Voltage” PID (commonly PID 0x14).
3. Record the voltage at idle and under a light load (≈ 2 kW).

If the reading stays below 0.5 V or jumps erratically, the sensor or its wiring is suspect.

Step 3 – Voltage Test

1. Re‑connect the battery.
2. Set a digital multimeter to DC voltage (0‑10 V range).
3. Probe the sensor’s signal wire (refer to the vehicle’s wiring diagram for pin identification).
4. Compare the measured voltage to the spec sheet.

A steady 0.5‑5 V reading indicates a healthy sensor; a value under 0.2 V confirms a low‑input condition.

Step 4 – Wiring Inspection

1. With the engine off, unplug the sensor connector.
2. Use the multimeter’s continuity mode to check the ground path to chassis ground.
3. Measure resistance; values higher than 5 Ω suggest corrosion or a broken wire.

If you find high resistance, clean the connector, replace the damaged wire section, or install a repair kit.

Step 5 – Component Replacement

1. Remove the old sensor using the appropriate socket (often 10 mm).
2. Apply a thin coat of anti‑seize compound to the new sensor’s threads.
3. Torque the sensor to the manufacturer’s spec (usually 15‑20 Nm).
4. Re‑connect the harness, re‑attach the battery, and clear the DTC with the scanner.

After the repair, verify live data for a stable voltage and confirm that the check‑engine light stays off after a short drive.

Advanced Testing Options

If the sensor and wiring are verified good, the PCM itself may be the culprit. Replacement of the PCM should be a last resort after confirming all other possibilities.

Cost Breakdown (DIY vs. Professional Shop)

Vehicle‑Specific Estimates

Labor rates vary by region. If you need a wiring harness repair, add roughly $45 – $80 for the extra time.

Emissions Impact

A malfunctioning knock sensor often forces the PCM to run a richer mixture to avoid knock. This richer mixture raises hydrocarbon emissions and can cause the “readiness monitors” for the catalytic converter and evaporative system to remain incomplete. so, the vehicle may fail a state emissions inspection until the code is cleared and the engine runs cleanly.

Driving Safety Assessment

The vehicle will usually start and idle, but a low‑input knock sensor can cause intermittent misfires under load. Prolonged misfires increase the risk of piston‑ring wear, overheating, and catalytic‑converter damage. Short trips are generally safe, but extended highway driving on a faulty sensor is not advisable.

Preventive Maintenance Checklist

• Spark plugs: Replace every 30 000 mi or as recommended. Fouled plugs can mask knock sensor symptoms.
• Fuel octane: Use the manufacturer‑specified grade; low‑octane fuel encourages knock.
• Sensor area: Keep the sensor clean of oil and coolant splatter; contaminants degrade the piezoelectric element.
• Wiring harness: Inspect during routine under‑hood checks, especially after exposure to road salt or after a collision repair.

Frequently Asked Questions

Q: Can a weak ignition coil trigger P0332? A: Yes. A coil that cannot produce a strong spark reduces engine vibration, which may lower the sensor’s voltage output. Test coil voltage if the sensor checks out.

Q: How does P0332 differ from P0330? A: P0330 monitors Knock Sensor 1 (bank 1). P0332 monitors Knock Sensor 2 (bank 2). Both use the same diagnostic approach but refer to different sides of the engine.

Q: Will clearing the code without fixing the issue work? A: The PCM will store the code again after a few drive cycles if the underlying problem remains. Re‑setting the code only masks the symptom temporarily.

Q: Is a PCM replacement covered under warranty? A: Many manufacturers provide a 2‑year/24 000‑mile power‑train warranty that may cover PCM failures. Verify coverage before ordering a new unit.

Safety Reminders While Working

• Battery disconnect: Remove the negative terminal and wait five minutes before touching any electrical components.
• Hot exhaust: Allow the exhaust manifold to cool for at least 15 minutes after a drive; contact with a hot surface can cause burns.
• Jack stands: If you must lift the vehicle, place it on sturdy jack stands before crawling underneath. Never rely on a hydraulic jack alone.
• Fuel system: Work in a well‑ventilated area, keep sparks away from the fuel tank, and avoid spraying fuel on hot components.

Final Thoughts

P0332 signals a low‑input voltage on the knock‑sensor 2 circuit for bank 2. By following the visual inspection, live‑data review, voltage test, wiring check, and sensor replacement steps, most DIY enthusiasts can resolve the issue in under an hour. Remember to disconnect the battery, respect hot‑exhaust components, and use proper jack stands when lifting the vehicle. Prompt repair preserves fuel efficiency, keeps emissions within legal limits, and protects the engine from knock‑related damage.

Related Powertrain Ignition codes

• P0300 Code — Random/Multiple Cylinder Misfire Detected (Causes & How to Fix)
• P0301 Code — Cylinder 1 Misfire Detected (Causes & How to Fix)
• P0302 Code — Cylinder 2 Misfire Detected (Is It Serious? How to Fix)
• P0303 Code — Cylinder 3 Misfire Detected (Causes & How to Fix)
• P0304 Code — Cylinder 4 Misfire Detected (Causes & How to Fix)