Engine

P0332 — Knock Sensor 2 Circuit Low Input (Bank 2)

Severity: medium Drive with care, to a shop

What P0332 means

The engine control module monitors the signal voltage from the knock sensor mounted on the bank 2 side of the engine block. The sensor is a piezoelectric element that turns block vibration into an electrical signal, which the ECM uses to detect knock and adjust ignition timing. P0332 sets when that signal stays below the expected range, due to an open circuit, a short to ground or a failed sensor.

Symptoms

  • Check engine light on
  • Reduced power or sluggish acceleration
  • Worse fuel economy
  • Pinging or knocking noise under load
  • Rough idle
  • Hesitation when accelerating

Possible causes

  1. Failed bank 2 knock sensor
  2. Open circuit or short to ground in the sensor wiring
  3. Corroded or loose connector terminals
  4. Sensor loose or tightened to the wrong torque
  5. Faulty ECM input circuit (uncommon)
  6. Noise from other sources, such as an exhaust manifold leak
  7. Underlying engine problems like a lean mixture, overheating or EGR faults

How to diagnose

  1. Scan for codes and freeze frame data, and note any lean, misfire or overheating codes
  2. Inspect the knock sensor harness and connector for chafing, oil, heat damage and corrosion
  3. Check that the sensor is secure, clean underneath and tightened to the factory torque
  4. Measure sensor resistance and compare it to the spec for your vehicle
  5. Test the signal circuit for opens and shorts to ground, and check reference voltage if the circuit uses one
  6. Tap the block near the sensor and watch the scan tool for a signal response
  7. Check the exhaust manifold for leaks that can create false noise
  8. If wiring and sensor are good, evaluate the ECM

Common fixes

  • Replace the bank 2 knock sensor and torque it to spec
  • Repair damaged wiring or replace a corroded connector
  • Fix an exhaust manifold leak or other source of noise
  • Replace or reprogram the ECM if it is confirmed faulty

Questions and answers

What does P0332 mean?

The ECM detected a signal that is too low in the knock sensor 2 circuit on bank 2. The cause is most often the sensor itself or its wiring.

Can I drive with P0332?

Short, careful trips are usually fine, but the engine runs with extra timing margin and loses power. Because knock could go undetected, don't put off the repair.

How do I tell a bad sensor from a wiring problem?

Inspect the connector and harness first, then measure the sensor's resistance and test the circuit for opens and shorts. If the wiring is good and the sensor is out of spec, replace the sensor.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.