P23xx codes: ignition coils and cylinder knock
48 codes in this range, all generic — the same meaning on every make. Misfire detection, ignition coils, crankshaft and camshaft position sensors and knock sensors. The engine computer detects misfires from dips in crankshaft speed, so this area often reports a problem that starts elsewhere — in the fuel supply or in compression.
What usually causes codes in this area
- Worn spark plugs and failing ignition coils
- Crankshaft and camshaft sensors and their wiring
- Fuel or vacuum problems that cause misfires
- Mechanical timing — a stretched chain or a worn belt
Can you keep driving?
Treat misfires as urgent: drive gently to a workshop, and stop if the check engine lamp flashes. A crankshaft-sensor fault can stall the engine without warning.
All P23xx codes
| Code | Meaning |
|---|---|
| P2300 | Ignition Coil "A" Primary Control Circuit Low |
| P2301 | Ignition Coil "A" Primary Control Circuit High |
| P2302 | Ignition Coil "A" Secondary Circuit |
| P2303 | Ignition Coil "B" Primary Control Circuit Low |
| P2304 | Ignition Coil "B" Primary Control Circuit High |
| P2305 | Ignition Coil "B" Secondary Circuit |
| P2306 | Ignition Coil "C" Primary Control Circuit Low |
| P2307 | Ignition Coil "C" Primary Control Circuit High |
| P2308 | Ignition Coil "C" Secondary Circuit |
| P2309 | Ignition Coil "D" Primary Control Circuit Low |
| P2310 | Ignition Coil "D" Primary Control Circuit High |
| P2311 | Ignition Coil "D" Secondary Circuit |
| P2312 | Ignition Coil "E" Primary Control Circuit Low |
| P2313 | Ignition Coil "E" Primary Control Circuit High |
| P2314 | Ignition Coil "E" Secondary Circuit |
| P2315 | Ignition Coil "F" Primary Control Circuit Low |
| P2316 | Ignition Coil "F" Primary Control Circuit High |
| P2317 | Ignition Coil "F" Secondary Circuit |
| P2318 | Ignition Coil "G" Primary Control Circuit Low |
| P2319 | Ignition Coil "G" Primary Control Circuit High |
| P2320 | Ignition Coil "G" Secondary Circuit |
| P2321 | Ignition Coil "H" Primary Control Circuit Low |
| P2322 | Ignition Coil "H" Primary Control Circuit High |
| P2323 | Ignition Coil "H" Secondary Circuit |
| P2324 | Ignition Coil "I" Primary Control Circuit Low |
| P2325 | Ignition Coil "I" Primary Control Circuit High |
| P2326 | Ignition Coil "I" Secondary Circuit |
| P2327 | Ignition Coil "J" Primary Control Circuit Low |
| P2328 | Ignition Coil "J" Primary Control Circuit High |
| P2329 | Ignition Coil "J" Secondary Circuit |
| P2330 | Ignition Coil "K" Primary Control Circuit Low |
| P2331 | Ignition Coil "K" Primary Control Circuit High |
| P2332 | Ignition Coil "K" Secondary Circuit |
| P2333 | Ignition Coil "L" Primary Control Circuit Low |
| P2334 | Ignition Coil "L" Primary Control Circuit High |
| P2335 | Ignition Coil "L" Secondary Circuit |
| P2336 | Cylinder 1 Above Knock Threshold |
| P2337 | Cylinder 2 Above Knock Threshold |
| P2338 | Cylinder 3 Above Knock Threshold |
| P2339 | Cylinder 4 Above Knock Threshold |
| P2340 | Cylinder 5 Above Knock Threshold |
| P2341 | Cylinder 6 Above Knock Threshold |
| P2342 | Cylinder 7 Above Knock Threshold |
| P2343 | Cylinder 8 Above Knock Threshold |
| P2344 | Cylinder 9 Above Knock Threshold |
| P2345 | Cylinder 10 Above Knock Threshold |
| P2346 | Cylinder 11 Above Knock Threshold |
| P2347 | Cylinder 12 Above Knock Threshold |
Read the codes from your own car
Plug an inexpensive Bluetooth LE or Wi-Fi OBD2 adapter into the port under the dashboard, and Brimly on your iPhone reads the stored, pending and permanent codes, explains each one offline and clears them once the fault is fixed. OBD diagnostics are part of Brimly Forever, a one-time purchase.
Requires iOS 18.1 or later. Free to download, with optional in-app purchases.