P0335
Knock Sensor 2 Circuit Intermittent (Bank 2)
Powertrain Ignition System Knock Detection 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

The knock sensor on bank 2 is sending an inconsistent or weak signal to the engine computer, like a radio that keeps cutting in and out. This prevents the ECU from properly detecting engine knock and adjusting ignition timing.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light illuminated
Engine pinging or knocking under acceleration
Reduced fuel economy
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Embedded Systems Insight
What the ECU/ECM is actually computing

The knock sensor detects vibrations from abnormal combustion and sends voltage signals to the ECU. The ECU expects a consistent signal pattern within a specific frequency range (typically 5-15 kHz). An intermittent circuit means the signal drops in and out, triggering a fault.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Knock Sensor Signal Voltage 0.5-4.5V AC with consistent frequency Intermittent drops below 0.2V or signal loss for >100ms
Signal Frequency Stability 5-15 kHz continuous during combustion Frequency dropout or amplitude collapse
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Knock sensor connector
Inspect and reseat the connector at the knock sensor on bank 2; clean any corrosion with electrical cleaner.
2
Engine wiring harness
Check the knock sensor wiring for cracks, loose connections, or pinches between engine and firewall.
3
Knock sensor
Replace the knock sensor on bank 2 if wiring tests pass and signal remains intermittent.