What P0324 means
P0324 concerns the knock control as a whole rather than a single sensor circuit.
How the engine computer detects it
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).
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Loss of power from ignition retard
- Audible pinging or knocking under load
- Higher fuel consumption
Common causes
- Genuine knock: low-octane fuel, carbon deposits, high intake or coolant temperature, lean mixture Most likely
- Mechanical noise taken for knock (loose parts, brackets, valve train, bearings) Possible
- Knock sensor damaged, wrongly torqued or mounted with sealant Possible
- Engine software or calibration Less likely
How to diagnose P0324
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: knock control, knock sensors, engine control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 3
- Ignition system or misfire
- 24
- Specific fault
Questions drivers ask
Can I drive with code P0324?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0324?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0324. They can point to a shared cause, so it's worth checking them together.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.