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P0328: Knock Sensor 1 Circuit High Input (Bank 1)

ModeratePowertrainDIY: Moderate

Can you still drive? Yes, but performance will be significantly reduced due to timing retard. If actual knock is occurring, switch to higher octane fuel immediately.

What Does P0328 Mean?

Code P0328 is set when the knock sensor on bank 1 reports a higher voltage than the ECM expects. This could indicate actual engine knock, a short in the sensor circuit, or electrical interference from other components. The ECM may aggressively retard timing in response.

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Common Causes

  • Actual engine knock from low-octane fuel
  • Short circuit in sensor wiring
  • Faulty knock sensor generating false high signal
  • Electrical interference from aftermarket accessories
  • Loose sensor mounting

Symptoms

  • Check engine light on
  • Significant loss of power
  • Poor fuel economy
  • Engine timing over-retarded
  • Hesitation on acceleration

Diagnostic Steps

  1. 1Check if low-octane fuel was recently used
  2. 2Inspect knock sensor wiring for shorts to voltage
  3. 3Test knock sensor signal with scan tool while tapping near sensor
  4. 4Check for aftermarket electrical accessories causing interference
  5. 5Verify sensor mounting torque

Recommended Parts & Tools

Estimated Repair Cost

TypeEstimated Cost
Total Repair Cost Range$50 - $400

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Commonly Affected Vehicles

Toyota 4RunnerLexus ES350Chevrolet TahoeNissan Pathfinder

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Frequently Asked Questions

Can bad gas trigger P0328?

Yes, using fuel with a lower octane than recommended can cause real engine knock, which the sensor correctly detects. Try a tank of premium fuel before replacing the sensor.

Will P0328 cause engine damage?

If the high signal is from actual knock and the ECM doesn't retard timing enough, detonation can damage pistons and bearings. Address this code promptly.

Community Fix Reports

Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.

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