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OBD-II Code

P0324

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$150–$900

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0324 means the Knock Control System has reported an internal error — the PCM ran its self-test on the knock-detection circuit (typically at key-on or during a specific RPM/load window) and either the knock signal processor failed its diagnostic check, or the PCM cannot establish a baseline noise floor against which to compare incoming knock events.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

  1. Note every code that is set, not just this one.

    Codes that appear together usually narrow the cause faster than any one of them read alone.

  2. Read the freeze frame — the conditions the fault was recorded under.

    Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.

  3. Confirm the fault is current rather than history.

    Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.

  4. Then follow the diagnostic notes further down this page, in the order they are written.

    They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

  • Check engine light
Read the full diagnostic procedureP0324 means the Knock Control System has reported an internal error — the PCM ran its self-test on the knock-detection circuit (typically at key-on o…

P0324 means the Knock Control System has reported an internal error — the PCM ran its self-test on the knock-detection circuit (typically at key-on or during a specific RPM/load window) and either the knock signal processor failed its diagnostic check, or the PCM cannot establish a baseline noise floor against which to compare incoming knock events. This is different from P0325 (circuit-level fault on a specific sensor) — P0324 is a system-level integrity code.

Cheapest-first ladder

  1. scan live data and look at the knock retard value (should sit at 0 degrees BTDC at idle, ramp 0 to 5 degrees BTDC under moderate load, and only spike to 5 to 15 degrees BTDC under heavy load with low-octane fuel).
  2. If knock retard is pinned at 0 even under WOT or pinned at maximum (often 10 to 15 degrees) at idle, the system has lost its reference.
  3. Check knock sensor signal voltage at the PCM connector — healthy piezoelectric knock sensors produce a 0 to 5 V AC signal proportional to vibration, with a baseline of roughly 0.5 to 1.5 V at idle and clean peaks during throttle blips.
  4. Resistance to ground from the signal wire should be high (typically over 1 megohm at the sensor); a shorted-to-ground harness collapses the signal and makes the PCM unable to compute a baseline.
  5. Verify the knock sensor torque spec (usually 15 to 25 Nm — under or over-torque kills the piezo crystal's sensitivity).
  6. Expensive misdiagnosis caveat: on GM LSx trucks and Camaros, the knock-system error often points at the PCM itself when the actual fault is a corroded ground at the engine block strap; replacing a $400 PCM doesn't fix a $0 ground-cleanup issue, so always voltage-drop test the engine grounds before reflashing or swapping the PCM.
Vehicle-specific patterns2005-2014 GM LSx V8 (Silverado, Tahoe, Camaro, Corvette, Escalade with 5.3/6.0/6.2L) sees P0324 alongside P0325/P0332 when the under-intake knock-sen…
  • 2005-2014GM LSx V8 (Silverado, Tahoe, Camaro, Corvette, Escalade with 5.3/6.0/6.2L) sees P0324 alongside P0325/P0332 when the under-intake knock-sensor harness pigtail corrodes and shorts the signal to ground — the under-intake location is GM's chronic weak point and the harness pigtail is the consumable.
  • 2004-2010Ford 4.6/5.4L Triton (F-150, Expedition, Mustang GT) throws P0324 from the knock sensors mounted at the rear of each cylinder head where they're exposed to heat soak and corrode the connector.
  • 2007-2015Toyota 2GR-FE 3.5L V6 (Camry V6, Avalon, RAV4 V6, Sienna, Lexus ES350/RX350) throws P0324 from knock sensors buried in the valley under the intake plenum — replacement is a 6-8 hour job.
  • 2008-2013Nissan VQ35DE (Altima, Maxima, Pathfinder) throws P0324 from chafed knock harness against the intake bracket.

Estimated repair$150 to $900.

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