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P0332 – Knock Sensor 2 Circuit Low Input (Bank 2) (OBD2)

P0332 means "Knock Sensor 2 Circuit Low Input (Bank 2)". The voltage the control unit measures in the knock sensor circuit is below the permitted minimum. For a sensor this usually means the signal wire is shorted to ground or the reference voltage is missing; for an actuator, that its control wire is shorted to ground.

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P0332 quick summary

Fault codeP0332
MeaningKnock Sensor 2 Circuit Low Input (Bank 2)
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityMedium
Can I drive?Yes. The engine retards ignition to protect itself, so it has less power and uses more fuel. Use the correct octane fuel and avoid heavy loads until the fault is fixed.
Repair cost€30 – €500

How knock sensors protect the engine

The knock sensor listens for the metallic vibrations of uncontrolled combustion (knocking) so the engine control unit can retard ignition timing before damage occurs.

A knock sensor is a piezoelectric microphone bolted to the engine block. When combustion knocks, it produces vibrations at a characteristic frequency; the sensor turns them into a small AC voltage. The control unit filters this signal per cylinder and retards ignition timing on any cylinder that knocks.

Engines with two cylinder banks usually have one or two sensors per bank. If the control unit sees no signal, a signal outside its range, or an implausible signal, it stores a knock sensor code and retards the timing on all cylinders as a precaution. That protects the engine but reduces power and increases fuel consumption.

Typical causes are a failed sensor, a sensor tightened to the wrong torque, corroded connectors (knock sensors often sit low on the block, sometimes under the intake manifold) and damaged wiring. Real mechanical noises can also trigger knock codes.

Bank 2 is the cylinder row that does NOT contain cylinder 1, so this code only appears on V6, V8, V10, V12 and boxer engines.

On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 16716 (P0332). Both numbers mean the same fault.

Symptoms of P0332

  • Check Engine light on
  • Reduced power and sluggish acceleration
  • Higher fuel consumption
  • Audible pinking or knocking under load (if the protection is not working)
  • Sometimes no other symptoms

Most common causes of P0332 (most likely first)

Mechanic's Pro Tip

When replacing a knock sensor, clean the mounting surface to bare metal and use a torque wrench. A sensor that is just 'snug' or overtightened can report wrong values – and many repeat knock codes come from incorrect installation, not bad parts.

  1. 1.Signal or control wire shorted to ground

    Most likely

    Look for chafed insulation where the harness touches the engine, exhaust brackets or body edges.

  2. 2.Missing 5 V reference or supply voltage

    An open reference wire or a shorted sensor elsewhere on the same reference circuit can pull it down.

  3. 3.Internal short in the knock sensor

  4. 4.Failed knock sensor

    The piezo element cracks or the sensor ages.

  5. 5.Wrong tightening torque

    Knock sensors must be tightened to a specific torque; too loose or too tight changes the signal.

  6. 6.Corroded connector or damaged wiring

    Common when the sensor sits under the intake manifold and the connector collects water.

  7. 7.Real knocking or mechanical noise

    Low-octane fuel, carbon deposits, overheating or loose components can trigger the sensor.

Step-by-step diagnostic guide

  1. 1

    Read codes and knock retard data

    Read all codes and look at the knock retard values per cylinder in live data. Note whether the fault is electrical (low/high) or a range/performance code.

  2. 2

    Measure the signal voltage

    With the ignition on and the knock sensor plugged in, back-probe the signal wire. Then unplug it and check the reference/supply and ground wires separately.

    Multimeter: Signal near 0 V = short to ground or no reference. Reference wire: about 5 V with ignition on. Signal wire to ground with connector unplugged: no continuity.

  3. 3

    Inspect wiring and connector

    Inspect the knock sensor harness and connector for corrosion, oil and damage.

  4. 4

    Measure the sensor

    Check the sensor resistance and signal according to the specification.

    Multimeter: Many piezo knock sensors show a very high resistance (often in the megaohm range) or are checked by their AC output when tapping the block near the sensor – follow the manufacturer's test.

  5. 5

    Check mounting and torque

    Make sure the sensor surface is clean and the bolt is tightened to the specified torque (often around 20 Nm).

  6. 6

    Rule out real knocking

    Use the correct fuel, check for overheating and carbon deposits, and listen for mechanical noises before replacing the sensor.

Frequently asked questions

Can I keep driving with P0332?

Yes. The engine retards ignition to protect itself, so it has less power and uses more fuel. Use the correct octane fuel and avoid heavy loads until the fault is fixed.

How much does it cost to fix P0332?

Typical repair costs are 30 € – 500 €, depending on the cause and the vehicle. The most common fixes are: signal or control wire shorted to ground; missing 5 V reference or supply voltage; internal short in the knock sensor. Always confirm the cause with the tests above before buying parts.

Is a knock sensor code dangerous?

The code itself is not, because the control unit retards timing for protection. But if the sensor fails while the engine really knocks, the protection may be reduced, so fix it and use the correct fuel.

Why are knock sensors hard to replace?

On many V engines they sit under the intake manifold, so the manifold has to be removed. On in-line engines they are often easier to reach.

What is the difference between P0332 and similar codes?

P0332 belongs to a group of codes for the same component that differ in the type or location of the fault: P0328 – Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor); P0329 – Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor); P0330 – Knock Sensor 2 Circuit (Bank 2); P0331 – Knock Sensor 2 Circuit Range/Performance (Bank 2); P0333 – Knock Sensor 2 Circuit High Input (Bank 2); P0334 – Knock Sensor 2 Circuit Input Intermittent (Bank 2). The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.