Powertrain, generic · Ignition system or misfire

P0324 Knock/Combustion Vibration Control System Error

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P0324 concerns the knock control as a whole rather than a single sensor circuit. GM and Saab's GM-based engines set it when excessive knock persists on one cylinder – knock despite ignition retard, or mechanical noise taken for knock – for more than 8–10 s; GM's 2018 engines in the first trip, older ones after two. Older GM calibrations also flag an abnormally low or flat signal per cylinder here. Ignition is retarded. Typical causes are low-octane fuel, carbon deposits, high intake or coolant temperature, lean running, or loose parts and valve train noise. Ford does not use this code; GM reports internal processor faults separately (P06B6/P06B7).

Likely causes

Genuine knock: low-octane fuel, carbon deposits, high intake or coolant temperature, lean mixture
Mechanical noise taken for knock (loose parts, brackets, valve train, bearings)
Knock sensor damaged, wrongly torqued or mounted with sealant
Engine software or calibration

Symptoms

  • Check engine light on
  • Loss of power from ignition retard
  • Audible pinging or knocking under load
  • Higher fuel consumption

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

knock controlknock sensorsengine control module

Related codes

P0325P0326P0331P06B6P2336P0300

References: gsi.ext.gm.com, gsi.ext.gm.com, saabwisonline.com, saabwisonline.com.