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OBD-II Code

P0329

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.

P0329 means the Knock Sensor 1 circuit on Bank 1 is signaling intermittently — the sensor reads in-spec most of the time but drops out, spikes, or loses ground reference long enough for the PCM to flag a fault, then recovers.

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 procedureP0329 means the Knock Sensor 1 circuit on Bank 1 is signaling intermittently — the sensor reads in-spec most of the time but drops out, spikes, or lo…

P0329 means the Knock Sensor 1 circuit on Bank 1 is signaling intermittently — the sensor reads in-spec most of the time but drops out, spikes, or loses ground reference long enough for the PCM to flag a fault, then recovers. This is the harder-to-catch sibling of P0325 because the sensor often passes a resistance check at the bench but fails under engine vibration and heat.

Cheapest-first ladder

  1. scan live data with the engine warm and watch knock retard (0 degrees BTDC at idle, climbing 0 to 5 degrees BTDC under load, with peaks to 15 degrees BTDC) and knock counter (0 at idle, accumulating 50 to 200 counts only under hard acceleration).
  2. Wiggle-test the knock sensor harness with the engine running while watching the live data — momentary spikes in the counter or sudden retard pulls when you flex the harness mean chafed wiring.
  3. Backprobe the signal wire at the PCM connector with a scope: a healthy piezo signal sits at 0.5 to 1.5 V AC baseline and shows clean peaks during throttle blips; intermittent dropouts to 0 V or noise above 5 V peak-to-peak point at the harness.
  4. Resistance-check the signal wire to ground (should be over 1 megohm); a marginal short that drops below 500 kohm under heat is a chafed-harness signature.
  5. Verify the engine block ground strap voltage drop is under 0.1 V under cranking load — a corroded ground is a frequent intermittent.
  6. Expensive misdiagnosis caveat: intermittent knock codes on GM LSx and Ford Triton platforms are almost always a chafed harness ground rubbing against the cylinder head or the intake bracket — replacing the sensor without inspecting the entire harness routing guarantees the code returns within 1,000 miles.
Vehicle-specific patterns1999-2013 GM LSx V8 5.3/6.0/6.2L (Silverado, Tahoe, Suburban, Yukon, Camaro, Corvette) throws P0329 from chafed harness ground at the rear of the val…
  • 1999-2013GM LSx V8 5.3/6.0/6.2L (Silverado, Tahoe, Suburban, Yukon, Camaro, Corvette) throws P0329 from chafed harness ground at the rear of the valley where the knock harness exits past the firewall bulkhead — the harness pigtail kit fixes most cases without removing the sensors.
  • 2004-2010Ford 4.6/5.4L Triton (F-150, Expedition, Mustang GT) throws P0329 from heat-cycled wiring at the rear-of-head sensor where it crosses the exhaust manifold heat shield.
  • 2007-2015Toyota 2GR-FE 3.5L V6 (Camry V6, Avalon, RAV4 V6, Sienna, Lexus ES350/RX350) throws P0329 from valley-buried harness chafing against the intake plenum mounting tabs.
  • 2005-2012Nissan VQ35DE/VQ35HR (350Z, 370Z, Altima, Maxima, Murano, Pathfinder) throws P0329 from a known harness routing where the knock pigtail rubs against the intake manifold bolt — Nissan's standard fix is rerouting the harness and adding a protective sleeve.

Estimated repair$150 to $900.

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