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Common codes
P0420P0300P0171P0455P0442P0128P0401P0113

P0325: Knock sensor circuit malfunction (Bank 1)

Drive carefully. Get it checked within a week or two.

Can I drive with P0325?

Yes, but drive carefully and get it checked soon. The computer cannot detect engine detonation, backing off timing and reducing engine power.

What does P0325 mean?

P0325 stands for Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor).

Symptoms you may notice

  • Check engine light steadily illuminated
  • Slight hesitation or change in throttle response
  • Possible increase in fuel consumption

How much does it cost to fix?

Repair costs for code P0325 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:

  • Defective knock sensor
    $50-$160 common
  • Rodent-chewed wiring harness under intake manifold
    $60-$180 common
  • Corroded connector terminals
    $20-$60 possible
  • Improper torque on knock sensor bolt
    $20-$50 rare

What to do next

  1. Inspect wiring going into the engine valley for signs of rodent chewing.
  2. Check sensor resistance with a digital multimeter (usually high resistance or open circuit specs).
  3. Replace the knock sensor and torque to exact manufacturer specifications.
Last updated: October 2026

Related codes

P0330 P0300 P0171
General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.

About this code

Code P0325 means the PCM detects an electrical fault in the Bank 1 knock sensor circuit. The knock sensor acts as a microphone detecting metal pinging or detonation inside the cylinders. To protect the engine from destruction, the computer retards ignition timing, which makes the vehicle feel noticeably slower and sluggish on highway hills.