OBD-II trouble code
P0330: Knock Sensor 2 Circuit Malfunction (Bank 2)
The bank 2 knock sensor circuit has failed — the PCM is no longer hearing the engine on the side without cylinder 1. On V6 and V8 engines this means half of the engine is operating without knock protection, and the PCM defaults to conservative ignition timing across both banks.
Quick facts
- System
- Powertrain
- Category
- Knock & Other
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $1,000
- DIY difficulty
- Intermediate DIY
Browse every code in P0300–P0394, or start from the full code library.
What does P0330 mean?
P0330 is the bank 2 partner to P0325. Where P0325 covers the bank 1 knock sensor (or the single sensor on inline-four engines), P0330 specifically covers the bank 2 knock sensor on V6 and V8 engines. The PCM uses both sensors to listen for detonation on each bank independently — engines can knock asymmetrically, and bank-specific sensing lets the PCM pull timing on the affected bank without compromising the healthy bank's performance.
Bank 2 identification matters here as much as on the fuel trim codes. Bank 2 is the bank that does NOT contain cylinder 1. On a transverse V6 the two banks sit front and rear rather than left and right, and which one is bank 2 has to be read off the cylinder numbering rather than assumed — the answer is not the same across engine families and getting it backwards is the expensive mistake here. Toyota's 2GR-FE, for one, numbers cylinders 1, 3 and 5 down the rear bank, so bank 1 is against the firewall and **bank 2 is the front bank facing the radiator**. Other families number the other way round. Where bank 2 does turn out to be the buried rear bank, P0330 becomes the far more labour-intensive sister of P0325, because that sensor often needs the intake manifold or other components off to reach. On longitudinal V8s there is no single answer, and this is where people get caught out, because the two most common platforms number from opposite banks. GM LS engines put the odd cylinders on the driver's side, so cylinder 1 is on the left and bank 2 is the passenger side. Ford Modular engines (4.6 and 5.4) number cylinders 1 through 4 down the passenger bank, so cylinder 1 is on the right and bank 2 is the driver's side — the exact opposite of the GM arrangement. Chrysler's Hemi follows the GM convention, with cylinder 1 on the driver's side. Do not carry an assumption across from the last vehicle you worked on: confirm cylinder 1's location for this engine, then count.
The physical failure modes are the same as P0325, P0327, and P0328: aged piezo crystal inside the sensor, water-corroded connector (especially on GM LS-family trucks where both knock sensors share the under-intake well configuration), or harness damage between the sensor and the PCM. What changes is the labor depth, and it changes by access rather than by bank number: on a transverse V the buried bank is the expensive one, and whether that is bank 2 depends on where the manufacturer put cylinder 1.
Drivability symptoms mirror the other knock sensor codes. The engine runs, but the PCM falls back to conservative ignition timing across both banks (most PCMs treat any knock sensor circuit fault as a reason to retard timing globally, not just on the affected bank). Power drops slightly, fuel economy drops a couple MPG, throttle response may feel softer. Real damage from undetected detonation is the long-term risk, particularly under heavy load or with low-octane fuel.
One useful note about V8 platforms: GM LS trucks tend to set P0327 (bank 1) and P0330 (bank 2) together when the under-intake wells flood. If both codes are set on a GM LS engine, plan on replacing both sensors at once during the intake manifold removal — the labor is identical and the second sensor is almost guaranteed to fail within months of the first.
Common causes
- Failed bank 2 knock sensor — piezo crystal degraded internally, which is where most of these end up once the cheap checks are done
- Corroded bank 2 sensor on GM LS trucks where both sensors sit in under-intake wells prone to water ingress
- Open or shorted knock sensor signal wire in the bank 2 harness routing
- Failed bank 2 connector with corroded or pushed-back pins
- Loose bank 2 knock sensor — incorrect torque on previous repair affects mechanical coupling
- Aftermarket sensor of wrong specification installed on bank 2
- Shared 5V reference circuit fault affecting both banks (look for P0325 alongside)
- PCM signal-input fault on the bank 2 circuit (rare)
Symptoms
- Check Engine Light on
- Mild loss of power, particularly under load
- Reduced fuel economy
- Slightly delayed throttle response
- Engine sounds normal in most cases — no obvious driveability symptom
- Possible pinging under heavy load if real bank 2 detonation is occurring undetected
Diagnostic steps
- 1.Identify bank 2 correctly for your specific engine before starting, by locating cylinder 1 rather than by side. On transverse V6s the banks are front and rear and which is which varies by engine family — on Toyota's 2GR-FE, for instance, bank 2 is the front bank facing the radiator, not the firewall bank. On longitudinal V8s it depends entirely on the manufacturer's numbering and the common platforms disagree: bank 2 is the passenger side on GM LS and Chrysler Hemi, and the driver's side on Ford Modular. Wrong-bank repairs are expensive when the labor is heavy, and this is the step that prevents one.
- 2.Pull all codes. P0330 alone is the bank 2 specific case. P0330 with P0325 or P0327 may point at shared wiring or PCM-side issues affecting both banks.
- 3.On GM LS trucks, plan for intake manifold removal. Check the under-intake wells for water pooling before assuming the sensor is bad — water in the wells is the leading root cause and may require drainage cleanup as part of the repair.
- 4.Disconnect the bank 2 knock sensor connector and measure resistance across the sensor terminals, comparing against the figure for that exact part. An out-of-specification reading confirms a failed sensor — but understand what this test cannot do. A knock sensor is a piezo element, and its usual failure is a loss of output sensitivity rather than a change in resistance, so a reading inside the range does NOT clear the sensor. Treat resistance as a way to condemn, never as a way to exonerate.
- 5.To actually test output, watch the knock signal or the knock retard value on a scan tool while tapping the block near the sensor with a small wrench, engine idling. A healthy sensor produces a visible response; one that measures fine and stays silent is the failure resistance testing misses.
- 6.Check continuity from the PCM to the sensor with both ends disconnected and a meter across the conductor. Back-probing a connected circuit measures the path through the sensor, not the wire, so it cannot tell you whether the harness itself is intact — back-probe to observe the live signal, not to prove continuity.
- 7.Inspect the bank 2 sensor connector and harness routing — look for corrosion, oil contamination, chafe points.
- 8.If the sensor and wiring both test clean, suspect intermittent connector contact and clean the connector pins thoroughly.
- 9.When replacing the sensor, torque to spec — knock sensors rely on mechanical coupling and incorrect torque (either direction) affects function. After replacement, drive through heavy-load conditions to confirm the code stays off.
Repair cost
$150 – $1,000
Knock sensor part itself is $30-150. On engines where the bank 2 sensor is accessible (most longitudinal V8 platforms, some transverse engines with reasonable rear-bank access) total replacement is $200-400. On transverse platforms where bank 2 turns out to be the bulkhead bank, expect $400-700 because of access difficulty — but note that on Toyota 2GR-FE, Honda J35 and Nissan VQ35 bank 2 is the FRONT bank facing the radiator, exactly as stated above, so those engines fall in the lower band rather than this one. GM LS trucks where both sensors live under the intake run $500-1000 for the pair — most owners replace both sensors at once because the labor is identical. Wiring repair is $100-400.
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Related repairs
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.