P0329
Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)
Powertrain Ignition System Knock Detection Circuit 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

Your knock sensor is sending a signal that's too high, like a smoke detector that won't stop screaming. The engine computer can't properly detect engine knock (pre-detonation) to adjust timing safely.

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

The ECU monitors the knock sensor's voltage signal, which detects vibrations from engine detonation. When voltage exceeds the normal operating range, the ECU cannot reliably distinguish real knock events from electrical noise. This triggers the fault code as a safety measure to prevent incorrect ignition timing adjustments.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Knock Sensor Voltage 0.5–4.5 volts (typical AC signal centered) Above 4.8 volts or stuck high signal
Signal Frequency Range 5–15 kHz (detonation signature) Signal out of range or constant DC voltage
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Knock sensor wiring harness and connectors
Inspect and reseat the knock sensor connector; corrosion or a loose pin often causes high-voltage faults.
2
Knock sensor (Bank 1)
Replace the knock sensor if connector is clean but signal remains high; sensor internal failure is common.
3
Engine control module (ECM) wiring harness
Check ECM ground and power leads for corrosion or damage if sensor and wiring test normal.