What's the difference between P0333 and P0332?

They're opposite electrical faults on the same bank-2 knock sensor. P0332 is low input — the signal voltage dropped below the minimum, usually from a short to ground. P0333 is high input — the voltage rose above the maximum, usually from an open circuit: a broken wire, a disconnected or corroded connector, or a sensor that failed open internally. The direction matters diagnostically: P0333 tells you to hunt for a break in the circuit, while P0332 tells you to hunt for a short.

Does P0333 mean the sensor is bad, or could it be wiring?

High-input codes lean toward wiring as much as the sensor itself, because an open circuit reads as high voltage. A broken signal wire, a corroded connector that's lost continuity, or a backed-out pin all produce the same reading as a sensor that's failed open. That's why the diagnosis starts at the connector and wiring rather than automatically replacing the sensor — especially on GM LS trucks, where corroded under-intake connectors are a frequent culprit. Measure sensor resistance to separate a bad sensor from a bad circuit.

Can I keep driving with P0333?

Usually yes. Like the other knock codes, it disables a protection layer rather than a load-bearing system, so the engine runs on conservative fallback timing — a little less power, slightly worse economy. The longer-term risk is that genuine detonation on bank 2 goes undetected and can damage internal parts under heavy load, on hot days, or with low-octane fuel. On a healthy engine with good gas you can drive it for a reasonable period, but plan the repair rather than ignoring it.

How much does it cost to fix P0333?

The sensor is $30-150. On accessible engines (Subaru EJ, Nissan VQ35, some Honda V6) total repair runs $150-300. On GM LS trucks where the sensors live under the intake manifold, budget $500-800 because removing the intake dominates the labor, and replace both sensors at once while you're in there. Because high-input faults are often a broken wire or corroded connector rather than the sensor, a wiring repair in the $100-400 range is also a common outcome.

OBD-II trouble code

P0333: Knock Sensor 2 Circuit High Input (Bank 2)

The bank-2 knock sensor is reporting signal voltage above the PCM's maximum threshold — the opposite electrical fault from P0332. Where 'low input' usually means a short, 'high input' typically points to an open circuit: a broken wire, an unplugged connector, or a sensor that's gone open internally.

Quick facts

System: Powertrain
Category: Knock & Other
Severity: Medium severity
Drivable: Usually safe to drive short-term
Repair cost range: $150 – $800
DIY difficulty: Intermediate DIY

What does P0333 mean?

P0333 is the bank-2, high-input knock sensor code, and the most useful way to read it is in contrast with its low-input twin, P0332. Both codes involve the same sensor on the same bank — the piezo accelerometer bolted to the bank-2 side of the block that listens for detonation so the PCM can pull timing to protect the engine. The difference is the direction the circuit has failed. P0332 (low input) means the signal voltage fell below the floor, which usually means a short to ground. P0333 (high input) means the voltage climbed above the ceiling, which usually means the circuit has gone open — a broken or disconnected wire, a corroded connector that's lost continuity, or a sensor whose internal element has failed open. Knowing the code is 'high' tells you to look for a break in the circuit rather than a short, which narrows the hunt before you ever lift the intake.

As with the rest of the knock family, identifying bank 2 correctly comes first. Bank 2 is the head that does not contain cylinder 1, and which physical side that is depends on the engine — passenger side on most GM LS and Ford modular V8s, but front or rear on transverse V6s. Verify it for your engine rather than assuming.

The platform that dominates this code is the same one that dominates the rest of the knock family: 1999-2007 GM LS trucks and SUVs, where the knock sensors sit in wells under the intake manifold and corrode from trapped moisture. On those engines an 'open circuit' high-input reading is frequently a connector so corroded it has lost continuity altogether. Because reaching the sensor means removing the intake, the standard practice is to replace both knock sensors and refresh the connectors at the same time.

Driveability impact is mild and matches P0332 — slightly reduced power and economy from the conservative fallback timing, with the real exposure being undetected detonation on bank 2 under heavy load. The engine runs; it just runs a little dumber until the sensor circuit is restored.

Common causes

Open circuit in the bank-2 knock sensor wiring — broken or chafed-through signal wire
Disconnected or corroded connector that has lost continuity (common on GM LS trucks)
Bank-2 knock sensor failed open internally
Corroded sensor and connector from water pooling in the under-intake wells on GM LS engines
High resistance in the circuit from corroded pins or a poor ground
Loose sensor that has lost mechanical and electrical contact
Aftermarket knock sensor of incorrect specification or resistance
PCM signal-input fault (rare)

Symptoms

Check engine light on with P0333 stored
Mild loss of power, especially under acceleration
Reduced fuel economy
Slightly delayed throttle response
Possible audible pinging under heavy load if real detonation goes undetected on bank 2
Engine otherwise sounds and runs normally

Diagnostic steps

1.Confirm which physical bank is bank 2 on your engine — the head without cylinder 1 — using the firing-order diagram for your specific engine.
2.Pull all codes. P0333 alone is the classic bank-2 open-circuit case. P0333 with P0332 or the bank-1 codes can point at shared wiring or a PCM-side issue.
3.Because 'high input' suggests an open, start at the connector: inspect for corrosion, a backed-out or broken pin, or a connector that has worked loose. On GM LS trucks, expect to remove the intake to reach it.
4.Disconnect the bank-2 knock sensor connector and measure resistance across the sensor terminals. An infinite (open) reading confirms a failed sensor element.
5.If the sensor measures in spec, back-probe the signal wire from sensor to PCM and check for an open or high resistance along the run.
6.Check the sensor ground and mounting — a loose sensor or poor ground can read as high input.
7.When replacing, torque to spec and, on V-engines, replace both knock sensors together since the labor to reach them is shared.
8.Clear the code, drive through a heavy-load pull, and confirm it stays off.

Repair cost

$150 – $800

The bank-2 knock sensor part is $30-150. On engines where the sensor is accessible (many Subaru, Nissan VQ, some Honda V6), total replacement is $150-300. On GM LS trucks where the sensors sit under the intake manifold, expect $500-800 because the intake has to come off — and most owners replace both sensors and refresh the connectors at once. A pure wiring/connector repair (common with high-input open faults) can run $100-400 depending on how buried the break is.

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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.

Related codes

P0332 P0330 P0328 P0325 P0327 P0300