P0332moderate severityGenerally driveable

P0332 Code: Knock Sensor 2 Circuit Low Input (Bank 2)

Written in plain English and reviewed by the eli5cars editorial team · Last reviewed June 2026

What it means in plain English

Knock sensors are small microphones bolted to the engine block that listen for the distinctive high-frequency vibration of detonation, or engine knock — fuel igniting unevenly instead of burning smoothly. When the ECM hears knock, it pulls back ignition timing to protect the engine. On V6 and V8 engines there are usually two knock sensors, one per cylinder bank. P0332 means the signal from the Bank 2 sensor — the bank that does not contain cylinder #1 — is reading a voltage lower than the ECM expects, not that the engine is actually knocking. This is almost always a wiring, connector, or mounting problem rather than a sign of engine damage.

Most likely causes — ranked

#1 Damaged, corroded, or loose knock sensor wiring/connector

most likely

Fix: Knock sensor wiring runs through one of the hottest, most cramped parts of the engine, often under the intake manifold. Heat-cycling and vibration commonly crack the insulation or loosen the connector over years of use. Inspect the harness and connector for damage or corrosion; repair or replace any compromised sections. This is the cheapest and most common fix for a knock sensor circuit code.

DIY ~$20Shop ~$150

#2 Knock sensor not torqued to spec

likely

Fix: Knock sensors are sensitive to how tightly they're bolted down — both too loose and too tight can throw off the vibration signal they send. If the sensor or intake manifold has been worked on recently, check that the sensor bolt is torqued to the exact factory spec, which is usually fairly light — over-tightening can crack the sensor. Retorque to spec and clear the code.

0Shop ~$80

#3 Failed Bank 2 knock sensor 2

likely

Fix: If the wiring and torque check out, the sensor's internal piezoelectric element has likely failed and needs replacement. On many V6/V8 layouts, the Bank 2 sensor sits underneath the intake manifold, which usually has to come off to reach it — that's why shop labor costs run higher than the part itself.

DIY ~$80Shop ~$380

#4 Wiring harness short to ground or a PCM-side circuit fault

possible

Fix: Less commonly, a short to ground somewhere in the harness or a fault on the PCM's input circuit can cause a persistent low-voltage reading even with a good sensor. This requires a scan tool and wiring diagram to isolate properly — best left to a shop with the right diagnostic equipment if the sensor and wiring both test fine.

0Shop ~$250

Check engine light on? Get a free code scan

If your check engine light is on, most auto-parts stores (AutoZone, O'Reilly, Advance) will read the code for FREE — no purchase required, just walk in. Bring the code back here and look it up at eli5cars.com/obd2 for the plain-English explanation.

Note: a scan only helps when there's an active fault code. For purely mechanical symptoms (noises, vibrations, leaks), a scan may show nothing — the suspects listed above are your starting point.

Want to read the codes yourself?

First, the free option: AutoZone, O’Reilly, and Advance Auto Parts read your codes for free — no purchase needed. That’s the cheapest way to get the code to look up here. If you’d rather have your own so you can check anytime (and clear a code after a fix), the Veepeak OBDCheck BLE is an inexpensive, reliable plug-in reader that pairs with a free phone app and works on any car sold since 1996.

See the Veepeak OBD2 scanner on Amazon

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Frequently asked questions

Is P0332 dangerous — is my engine actually knocking?

Not necessarily. This code reports a wiring or signal problem with the sensor circuit, not a confirmed detonation event. That said, because the ECM can't hear real knock without a working sensor, it's smart to get this fixed soon rather than driving indefinitely with reduced knock protection.

Can I drive with P0332?

Yes, in most cases. The engine still runs, though the ECM may run a more conservative, timing-retarded strategy on Bank 2 as a safety precaution, which can slightly reduce power and fuel economy.

Which side is Bank 2?

Bank 2 is whichever side of a V-configuration engine does not contain cylinder #1. The exact physical side — driver's vs. passenger's — depends on the manufacturer and engine. Check your owner's manual or a service diagram for your specific vehicle.

Why does the knock sensor sit under the intake manifold?

It needs to be bolted directly to the engine block, close to the combustion chambers, to accurately pick up detonation vibration. On many V6/V8 engines that spot happens to be underneath the intake manifold, which is why replacing a bad knock sensor often costs more in labor than the part itself.