P0330 code: Knock Sensor 2 Circuit (Bank 2)
P0330 means knock Sensor 2 Circuit (Bank 2). The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0330 means
Engines with two cylinder banks — V-type and flat engines — typically carry a knock sensor per bank so the computer can hear detonation on each side. P0330 means the circuit for knock sensor 2, on Bank 2 (the bank opposite cylinder 1), isn't reading correctly. The usual causes are a failed sensor or a wiring/connector fault; corrosion is common because these sensors live in a hot, harsh spot, and on many V engines that spot is the valley under the intake manifold. With the Bank 2 knock signal unusable, the computer retards ignition timing conservatively to protect the engine, which shows up as mild sluggishness and slightly worse fuel economy rather than dramatic symptoms. Because reaching the sensor is often the bulk of the labor, many shops replace both knock sensors while the intake is off.
P0330 symptoms
- Check-engine light, often with no obvious change
- Slight loss of power or acceleration
- Minor drop in fuel economy
- Occasional pinging under load if timing isn't protected
What it costs to fix P0330
Typical range: $150–$700 · about ~0.5–3 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Knock sensor (Bank 2) | $40–$200 | ~0.5–3 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
Labor dominates and varies wildly: on many V-type engines both knock sensors sit under the intake manifold, so the job is mostly disassembly — which is also why doing both sensors at once is common. Easy-access engines are far cheaper.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0330 for my exact vehicle →
How to fix P0330
Advanced — usually a shop job unless you’re well equipped
- Find where your engine mounts the Bank 2 sensor
Bank 2 is the bank without cylinder 1, so P0330 only shows up on V and flat engines. Check service info before planning anything: some put knock sensors on the outer side of the block, reachable from underneath, while many V6 and V8 designs bury them in the valley under the intake manifold — the difference between an hour and most of a day.
- Test through the nearest reachable connector
Valley-mounted sensors often connect through a short jumper harness that plugs into the engine harness at the back or side of the intake. Measure the Bank 2 sensor from that plug, then measure the Bank 1 sensor the same way; matching readings that also meet spec mean the sensor and jumper are likely fine and the fault lies between there and the computer.
- Check the computer-side wiring for opens and shorts
With the battery disconnected, ohm each Bank 2 knock wire from that junction to the computer connector, and check for continuity to ground and to neighbouring circuits. Look closely at the connector bodies too: water or coolant that collects in the valley commonly rots these terminals, and coolant residue around the intake is a clue.
- Replace both sensors and the jumper while the intake is off
If the fault is under the manifold, pull the intake and replace the Bank 2 sensor, its Bank 1 partner, and the jumper harness in one go — the labor is the expensive part, so doing them together makes sense. Clean the mounting bores, torque the sensors exactly to spec, and fit new intake gaskets.
- Confirm timing advance comes back after the repair
After clearing the code, drive with live data showing spark advance and knock retard, split by bank where the scan tool allows. Timing should advance normally on light throttle with little or no retard and no returning code; persistent retard with clean wiring and new sensors suggests real detonation, poor fuel, or carbon build-up worth investigating.
DIY or shop? Diagnosis from the accessible jumper connector is reasonable for a home mechanic with a multimeter and a wiring diagram, and when the Bank 2 sensor is on the outside of the block, replacement is DIY too. When it's in the valley, the job means removing the intake (and on some engines the fuel rail or coolant passages), new gaskets, and a careful torque sequence — a mistake there leaves vacuum or coolant leaks. That's where most owners should hand it to a shop and have both sensors done at once.
Tools for the DIY steps: Digital multimeter · Wiring diagram for the knock circuits · Torque wrench · Socket set with extensions and swivels · Intake manifold gasket set (for valley-mounted sensors) · Scan tool with timing and knock data
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0330.
Start a case with P0330 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0330?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0330: common questions
Why does my engine have two knock sensors?
V-type and flat engines have a cylinder bank on each side, and one sensor can't reliably hear knock across the whole engine. Sensor 1 covers Bank 1 (the side with cylinder 1) and sensor 2 covers Bank 2 — P0330 is the Bank 2 side.
Can I drive with P0330?
No code can settle that by itself. Losing a knock signal makes the computer run more conservative timing to protect the engine, so it may feel slightly less peppy and efficient. Get it fixed sooner if you hear pinging under load.
Should I replace both knock sensors at once?
If your sensors are under the intake manifold, it's often sensible — the labor to get there is the main cost, and the second sensor of the same age is a cheap add while everything is apart. On engines where sensors are easy to reach, replace only the failed one.
Is P0330 the sensor or the wiring?
Either. The sensor is the common failure, but corroded connectors and chafed wiring in the hot engine valley mimic it exactly. Since reaching the sensor can be laborious, a shop will usually test the circuit before committing to intake removal.
Symptoms that trigger P0330
Drivers who get this code often notice one of these. Each has its own causes and cost guide:
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0330 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0330 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.