P0333 medium Severity

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

Check Engine Light illuminated; potential engine pinging, reduced power, and timing adjustment issues

Overview

P0333 generic OBD-II knock sensor 2 circuit high input Bank 2 excessive voltage signal from knock sensor causing performance issues

Common Symptoms

  • Check Engine Light illuminated
  • Engine knocking or pinging noises
  • Loss of engine power or reduced performance
  • Irregular RPM or rough idle
  • Decreased fuel economy

Most Common Causes

Faulty knock sensor 2 (Bank 2) high

Sensor producing excessively high voltage signal to PCM

Damaged or corroded wiring/connectors in knock sensor circuit high

Includes shorts to voltage or ground and poor connections

Loose sensor mounting or improper installation medium

Poor mechanical connection can distort readings

Incorrect fuel octane or engine detonation (actual knock) medium

Can trigger high input signals from sensor

Faulty or misprogrammed PCM/ECM low

Considered after sensor and wiring ruled out

Diagnostic Steps

  1. Connect OBD-II scanner and confirm P0333 and any related codes
    Expected: Code P0333 present; note freeze frame data
    Interpretation: Confirms sensor high input fault
  2. Visually inspect knock sensor wiring and connectors on Bank 2
    Expected: Check for damaged insulation, corrosion, loose pins
    Interpretation: Faulty wiring/connectors likely if damage found
  3. Measure sensor signal voltage and resistance with a multimeter
    Expected: Voltage outside manufacturer spec or abnormal resistance
    Interpretation: Sensor out of spec indicates replacement
  4. Check engine mechanical and fuel quality for potential knocking
    Expected: Unusual engine vibration or use of low octane fuel
    Interpretation: Engine condition may contribute to false high signals
  5. If all else normal, test or reprogram PCM/ECM
    Expected: Verify PCM handling knock sensor data correctly
    Interpretation: PCM fault possible if hardware/software anomaly

Repair Solutions

Replace knock sensor 2 on Bank 2 medium
Estimated Cost: $70 - $250

Typical cost for sensor part; labor depends on accessibility

Repair or replace damaged wiring/connectors medium
Estimated Cost: $50 - $200

Costs vary by extent of wiring harness damage

Correct engine mechanical issues and use proper octane fuel varies
Estimated Cost: $0 - $500

Depends on root mechanical issues and service

Reprogram or replace PCM/ECM hard
Estimated Cost: $200 - $1200

High cost; only after ruling out sensor/wiring problems

Common Misdiagnoses

Avoid these common diagnostic mistakes:

  • Misinterpreting actual engine knock noise as sensor electrical fault

Frequently Asked Questions

What does a P0333 diagnostic trouble code signify?

Knock Sensor 2 Circuit High Input (Bank 2) is the standard definition for P0333. This diagnostic code is triggered when the ECU detects a problem in the Sensors.

How serious is the P0333 code?

The P0333 code is considered medium severity. Check Engine Light illuminated; potential engine pinging, reduced power, and timing adjustment issues

What are the symptoms of P0333?

Drivers often report: Check Engine Light illuminated, Engine knocking or pinging noises, Loss of engine power or reduced performance when this code is present.

Common triggers for the P0333 error

Potential culprits include: Faulty knock sensor 2 (Bank 2), Damaged or corroded wiring/connectors in knock sensor circuit, Loose sensor mounting or improper installation. A proper diagnosis is recommended.

How much does it cost to fix P0333?

The cost varies significantly based on the root cause. For example, replacing a Repair or replace damaged wiring/connectors typically costs between $50 and $200, while fixing a Reprogram or replace PCM/ECM can range from $200 to $1200.

Is the P0333 code specific to Mercedes?

Yes, P0333 is a generic code that applies to all OBD-II compliant vehicles, including Ford, Toyota, Honda, Chevrolet, Nissan, Dodge, BMW, and more.

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