P0332 Code: Knock Sensor 2 Circuit Low Input Bank 2

The P0332 code means your engine control module is receiving a signal from the knock sensor 2 circuit on bank 2, but that signal is lower than the minimum expected threshold. The P0332 code sits in a family of knock sensor faults — it’s the bank 2 equivalent of the P0327 code, which covers the same low input condition on bank 1.

Where the P0331 code flags a signal that’s outside the performance range in either direction, the P0332 code is specifically a low signal fault. The circuit is connected, the sensor is producing something, but the voltage arriving at the ECM is too weak for knock detection to work reliably.

When the P0332 code is stored, the ECM can’t tell whether bank 2 is knocking or not. A detonation event that should produce a detectable voltage spike generates nothing significant enough for the ECM to act on. The ECM’s response is to default to conservative ignition timing — retarding more than necessary to protect the engine from undetected knock. The result is reduced power and worse fuel economy until the P0332 code is resolved.

Understanding what drives the bank 2 signal low is the fastest path to fixing this fault. In most cases it comes down to one of three things: a weakening sensor, a short to ground pulling the voltage down, or a sensor that isn’t properly torqued to the engine block.

What You’ll Notice

• Check engine light on
• Reduced engine power, especially under load on bank 2 cylinders
• Noticeably worse fuel economy
• Engine feels flat and unresponsive during acceleration
• Possible pinging or knocking under heavy throttle, particularly with lower octane fuel
• Symptoms tend to be consistent rather than intermittent — the P0332 code usually produces a steady low signal
• No stalling or rough idle in most cases

The consistent nature of symptoms associated with the P0332 code is a useful diagnostic clue. Unlike range codes that produce variable symptoms, a low signal condition is usually constant once established. If the power loss and fuel economy drop appeared suddenly and haven’t changed since, P0332 is a strong candidate.

Bank 2 — Which Side?

The P0332 code targets bank 2 — the side of the engine that does not contain cylinder 1. On most vehicles bank 2 is the passenger side, but this varies by manufacturer. Always confirm in your vehicle’s service manual before beginning any work on the P0332 code.

On inline engines with two knock sensors, the P0332 code refers to the second sensor rather than a separate cylinder bank. Most 4-cylinder engines have only one knock sensor and won’t produce this code — P0332 is primarily a V6, V8, and inline 6 fault.

How the Knock Sensor Signal Works

The knock sensor is a piezoelectric device. When engine knock occurs — the abnormal vibration of uncontrolled detonation — the sensor vibrates and generates a small voltage. The ECM reads this voltage and adjusts ignition timing in real time to stop the knock before it causes damage.

The ECM has a defined minimum threshold for the knock sensor signal. Below that threshold, the signal is too weak to use for knock detection. The P0332 code is stored when the bank 2 signal consistently falls below this minimum — meaning bank 2 has no meaningful knock protection.

According to SAE J1979 OBD-II standards, a low input code like P0332 means the signal voltage is chronically below the minimum expected value for reliable knock detection on bank 2.

What Usually Causes the P0332 Code

1. Faulty bank 2 knock sensor producing a weak signal The most common cause of the P0332 code. A knock sensor whose piezoelectric element has degraded produces a weaker signal than required. This degradation is accelerated by overheating, high mileage, and repeated heat cycling. The bank 2 sensor produces a signal that falls below the ECM’s minimum threshold, and the P0332 code is stored. On high-mileage Toyota, Lexus, and Nissan V6 engines, this is by far the most frequently encountered cause.

2. Short to ground in the bank 2 signal wire A short to ground pulls the signal voltage toward zero regardless of what the sensor produces. Even a perfectly functional sensor can’t overcome a grounded signal wire — the P0332 code is inevitable in this scenario. This is one of the first things to check with a multimeter when the P0332 code appears, because a persistent short to ground can damage the ECM’s input circuit over time if left unresolved.

3. Undertorqued bank 2 knock sensor The knock sensor must be torqued to a precise specification — typically 15–20 Nm depending on the manufacturer. A sensor that’s been undertorqued after a previous repair, or that has loosened due to engine vibration, doesn’t maintain proper metal-to-metal contact with the block. Without solid contact, vibration transfer is inefficient and the signal amplitude drops below the P0332 threshold. This is the cheapest possible cause of P0332 to fix — always verify torque before replacing anything.

4. Corroded or high-resistance connector Corrosion on the bank 2 knock sensor connector terminals introduces resistance into the signal path. Resistance attenuates the voltage — a signal that left the sensor at an acceptable level arrives at the ECM below the minimum threshold, triggering the P0332 code. Connector corrosion is particularly common on vehicles in high-humidity climates, coastal areas, or regions that use road salt heavily.

5. Wrong replacement sensor If the P0332 code appeared after a knock sensor replacement, the new sensor may be the wrong specification. Different engines use flat-response sensors or resonant sensors tuned to specific frequencies. Installing the wrong type produces an output that’s either too weak or in the wrong frequency range for the ECM — causing P0332 even though the new sensor is undamaged. Always verify the part number matches the original.

6. Internal sensor wiring break The wiring inside the knock sensor body can develop an internal break without any visible external damage. The sensor may test within resistance specification at the connector but produce no meaningful signal under operating conditions. This internal fault is best confirmed with an oscilloscope signal test rather than a static resistance check.

7. Oil or coolant contamination On some engine layouts, the bank 2 knock sensor is mounted where it can be exposed to oil seepage or coolant leaks. Contamination of the sensor or connector causes progressive corrosion and signal degradation that eventually produces the P0332 code. If you find evidence of contamination near the bank 2 sensor, fix the leak source before replacing the sensor — otherwise the new unit fails the same way.

How Serious Is the P0332 Code?

The P0332 code is serious — and its consistent low-signal condition means bank 2 has no knock protection at all while the fault is active.

The ECM’s conservative timing map reduces performance and fuel economy, but it doesn’t fully substitute for a functioning knock sensor. Any actual detonation event that occurs on bank 2 while the P0332 code is stored goes undetected and uncorrected. Sustained knock causes cumulative damage to pistons, connecting rod bearings, and cylinder walls — damage that’s expensive to repair and entirely preventable.

On V6 and V8 engines, the P0332 code leaves all bank 2 cylinders unprotected. Fix the P0332 code promptly rather than running on conservative timing indefinitely.

How to Diagnose the P0332 Code

Step 1 — Read all stored codes and freeze frame data

Confirm the P0332 code and check carefully for companion codes. The P0327 code alongside P0332 means both banks have low signal faults — pointing toward a common cause like a power supply issue or alternator interference rather than individual sensor failures. The P0330 code alongside P0332 indicates bank 2 has both a circuit fault and a low signal — suggesting significant sensor or wiring damage. Note the freeze frame conditions when the P0332 code was stored.

Step 2 — Check bank 2 sensor torque

Before any electrical testing, locate the bank 2 knock sensor and confirm it’s properly secured. A sensor that moves by hand is undertorqued and is a likely cause of the P0332 code. Retorque to specification with a torque wrench, clear the P0332 code, and test drive. If the code doesn’t return, undertorque was the cause.

Step 3 — Inspect the sensor and connector

With the bank 2 sensor located, inspect the sensor body for cracks, heat damage, or contamination. Check the connector for corrosion, moisture, and properly seated pins. Look for oil or coolant near the sensor mount. Clean any corrosion with electrical contact cleaner, reconnect firmly, and clear the P0332 code before retesting.

Step 4 — Check for a short to ground

With the bank 2 sensor disconnected, use a multimeter to measure resistance between the signal wire and a known good ground. Infinite resistance means no short — the wiring is clean. Any resistance reading indicates a partial short pulling the signal down and causing the P0332 code. Zero resistance means a direct short that must be repaired before fitting any new sensor.

Step 5 — Test bank 2 sensor resistance

Disconnect the sensor and measure resistance across the terminals. Compare to the manufacturer’s specification for your sensor type. Flat-response sensors used on Toyota and Lexus engines should read infinite resistance. Traditional piezoelectric sensors typically read between 100 kΩ and 10 MΩ. A reading outside the expected range confirms the bank 2 sensor has failed and is the direct cause of the P0332 code.

Step 6 — Oscilloscope signal test

Connect an oscilloscope to the bank 2 signal wire with the sensor connected and the engine running. Tap the engine block on the bank 2 side firmly with a wrench handle. A healthy sensor produces a clear voltage spike. A P0332 fault shows a spike that’s weaker than expected — or no spike at all. This test confirms the P0332 code diagnosis at the sensor level and distinguishes between a failed sensor and a wiring fault.

Step 7 — Monitor live data

Use a scan tool to graph bank 2 knock sensor voltage in live data during a drive. Compare it to the bank 1 signal under the same conditions. A bank 2 signal that stays near zero while bank 1 responds normally confirms the P0332 code is a bank 2 sensor or circuit issue rather than a system-wide problem.

Step 8 — Check wiring continuity

Test continuity between the bank 2 sensor connector and the ECM connector on the signal wire. No continuity means a broken wire causing the P0332 code. Also verify the reference voltage and ground wires are intact — a missing reference voltage on an active sensor produces a low output that triggers P0332.

Step 9 — Check the alternator

If the P0332 code appears alongside other intermittent sensor codes, test the alternator for AC ripple. More than 0.5V AC across the battery terminals with the engine running indicates a failing diode that may be contributing to the P0332 code through electrical interference on the knock sensor circuit.

How to Fix the P0332 Code

Retorque the bank 2 knock sensor — Always the first step. Free, fast, and resolves the P0332 code more often than most people expect. Use a torque wrench and confirm the correct specification for your engine.

Repair the short to ground — If a short was found during P0332 code diagnosis, locate the damaged section of harness and repair it using automotive-grade wire and connectors. Inspect the full harness routing for other chafe points. Verify the short is fully resolved before fitting a new sensor.

Clean or replace the connector — If corrosion is causing the P0332 code, clean the terminals thoroughly or replace the connector pigtail. A corroded connector that can’t be cleaned reliably needs full replacement.

Replace the bank 2 knock sensor — If the sensor is confirmed as producing a weak signal and torque and wiring are correct, replace it. Use an OEM or quality aftermarket sensor — cheap knock sensors are a common cause of the P0332 code returning after replacement. Verify the part number matches the original exactly.

Repair or replace the wiring harness — On Toyota and Nissan V6 engines, the updated harness kit addresses the root cause of the P0332 code permanently. For other vehicles, repair any damaged wiring sections with proper automotive materials.

Address oil or coolant leaks — If contamination caused the P0332 code, fix the leak source before fitting a new sensor.

P0332 on Specific Vehicle Makes

Toyota and Lexus V6 (1MZ-FE, 2GR-FE, 3GR-FSE): The P0332 code is very common on these engines alongside the P0327 code on bank 1. Both knock sensors sit under the intake manifold where the wiring harness degrades from heat exposure. Toyota’s updated harness kit covers both banks — replacing both sensors and the full harness in one service is the most cost-effective way to fix the P0332 code on these engines. Budget for 3–5 hours of labor for intake removal.

Nissan VQ V6 (Altima, Maxima, 350Z, 370Z, Pathfinder): Identical failure pattern to Toyota. The P0332 code on VQ engines almost always involves under-intake harness degradation. High-mileage VQ engines commonly develop sensor failures alongside the harness issues. Addressing both banks simultaneously is strongly recommended.

GM LS and LT V8 (Silverado, Tahoe, Camaro, Corvette): The P0332 code on LS engines appears from sensor degradation on high-mileage examples. The bank 2 sensor requires intake manifold removal for access but is inexpensive. Wiring faults are less common on LS engines than on Toyota and Nissan platforms.

Ford Modular V8 (Mustang GT, F-150, Explorer): The P0332 code on Modular engines is typically a sensor replacement. Connector corrosion is a known contributing cause in humid climates.

Subaru EJ and FA engines: Moisture intrusion near the bank 2 sensor is a known cause of the P0332 code on Subaru horizontally opposed engines. Inspect the mounting area carefully for water ingress when diagnosing this fault on Subaru vehicles.

BMW V8 and inline 6: On BMW engines with separate knock control modules, the P0332 code can originate in the module rather than the sensor itself. Check the module before replacing sensors when diagnosing P0332 on BMW vehicles.

What It Might Cost to Fix the P0332 Code

Costs vary by vehicle. Toyota and Nissan V6 engines with under-intake sensors require 3–5 hours of labor. Always get a vehicle-specific estimate for the P0332 code repair.

Related Codes

• P0324 — Knock Control System Error
• P0327 — Knock Sensor 1 Circuit Low Input Bank 1
• P0330 — Knock Sensor 2 Circuit Malfunction Bank 2
• P0331 — Knock Sensor 2 Circuit Range/Performance Bank 2
• P0333 — Knock Sensor 2 Circuit High Input Bank 2
• P0325 — Knock Sensor 1 Circuit Malfunction Bank 1
• P0300 — Random/Multiple Cylinder Misfire Detected

Frequently Asked Questions

Can I drive with the P0332 code? Short necessary trips are possible since the ECM defaults to conservative timing. But bank 2 has no knock protection, and any detonation goes undetected. If you hear pinging under acceleration while this fault is active, reduce load immediately. Don’t leave the P0332 code unrepaired for long.

What’s the difference between the P0332 code and P0330? The P0330 code is a circuit malfunction — the signal is absent or the circuit has a definitive fault. The P0332 code is a low input — the circuit is working but the signal voltage is below the minimum threshold. P0332 is often caused by a weakening sensor or partial wiring fault, while P0330 more often indicates a complete failure.

Why did the P0332 code come back after I replaced the bank 2 sensor? Most likely a wiring fault — particularly on Toyota and Nissan V6 engines where the under-intake harness is the actual root cause. Also verify the replacement sensor part number matches the original exactly. Using the wrong sensor type causes P0332 to return immediately.

Should I replace both knock sensors when fixing the P0332 code? On Toyota and Nissan V6 engines — yes. Both sensors share the same under-intake environment and degrade at similar rates. If bank 2 has failed, bank 1 is usually close behind. On other vehicles with externally accessible sensors, replacing only the failed bank 2 sensor is reasonable.

Can undertorquing really cause the P0332 code? Yes — and it’s more common than people expect. The knock sensor detects vibration transmitted through the engine block. Without proper metal-to-metal contact from correct torque, that transmission is inefficient and signal amplitude drops below the threshold that stores P0332. Always use a torque wrench when installing knock sensors.

How long can I ignore the P0332 code? There’s no safe timeframe. The ECM’s conservative timing provides some protection but isn’t a substitute for a working sensor. Any knock event on bank 2 while the P0332 code is active goes undetected. Fix it at the first opportunity — it’s almost always an inexpensive repair that prevents a much more costly one later.

Will premium fuel help with the P0332 code? Premium fuel reduces knock frequency, which reduces knock sensor demand. But the P0332 code is a circuit fault — the signal is too low regardless of knock activity. Premium fuel won’t fix a weak sensor or a grounded wire causing P0332. It may slow symptom progression slightly, but it doesn’t address the root cause.

For detailed information on OBD-II standards and vehicle safety, visit the National Highway Traffic Safety Administration (NHTSA) or the SAE International standards library.

This guide is for informational purposes only. For an accurate diagnosis, always consult a qualified mechanic.