P0328 — Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)
P0328 sets when the knock sensor signal voltage is higher than the calibrated maximum. High input can be a short to power or a failed sensor. Always torque the new sensor to specification — incorrect torque changes the sensor's sensitivity. Rule out actual engine knock (carbon buildup, low octane, overheating) before replacing the sensor.
Fault Overview
Failed knock sensor, short to power on the signal wire, wiring damage near the block, poor sensor ground, and actual severe detonation are the primary causes.
Engine & Platform Coverage
Symptoms
- •P0328
- •knock sensor high input
- •knock sensor circuit high
- •P0328 Honda
- •P0328 Toyota
Possible Causes
- 1.Failed knock sensor
- 2.Short to power on the signal wire
- 3.Wiring damage near the block
- 4.Poor sensor ground
- 5.Actual severe detonation
Wiring & Circuit Notes
Knock sensor signal and ground circuits. Check for damage near the block.
DVOM Specs & Sensor Tests
Sensor voltage. Scope signal at idle and under load. Mounting torque.
Diagnostic Flow — FSM Sequence
AI Diesel Tech enforces this evidence-gate sequence. Each gate must pass before advancing.
4 steps locked behind Technician Mode- 1Step 1 — Inspect Wiring for Short to Power: Inspect the signal wire for short to power.
- 2Step 2 — Check Sensor Mounting and Torque: Check sensor mounting and verify torque to OEM specification.
- 3Step 3 — Scope the Signal: Scope the knock sensor signal at idle and under light load.
- 4Step 4 — Replace Sensor if Circuit Is Good and Signal Is Abnormal: Replace the knock sensor if the circuit is proven good and the signal is abnormal.
- 5Step 5 — Address Any Actual Detonation Causes: Address any actual detonation causes — carbon buildup, low octane fuel, or overheating.
Unlock the full evidence-gated diagnostic sequence, DVOM test steps, and repair procedures in Technician Mode.
Full Diagnostic Access
Verification steps, preventative measures, severity guidance, and legacy comparison are available in Technician Mode.
Typical Repair Costs
Repair wiring $50–200; replace knock sensor $50–300; correct mechanical knock causes $100–1,000+.
Related Codes & Pages
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Summary
Use the AI Diesel Tech diagnostic engine to run this code through a structured, evidence-gated sequence and get a confirmed root cause before any parts are replaced.