P2306: Ignition coil C primary control circuit low
The ECU sees a lower voltage than expected on the control line for ignition coil C. Usually a connector, wiring or coil fault.
| Code | P2306 |
|---|---|
| System | Engine and transmission |
| Group | P23xx, Ignition coils and engine |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P2306 means
The ECU fires each ignition coil by switching its primary circuit, the winding that carries the supply current. On coil C it has measured a voltage below the normal range, so it cannot drive the coil properly. Which cylinder coil C serves is set by each manufacturer.
Most common causes
- Coil connector loose, corroded or with a pushed-back pin
- Coil control wire chafed and shorting to earth
- Faulty ignition coil
- Poor supply or earth feeding the coil pack
- Internal fault in the ECU driver circuit (uncommon)
Symptoms
- Engine warning light on or flashing
- Rough idle and jerking
- Loss of power
- Engine runs as if a cylinder is missing
Can you drive with P2306?
With care If the engine runs smoothly you can drive to a garage, but do not leave it long. If the warning light flashes or the engine shakes, a cylinder is misfiring and can damage the catalytic converter, so stop driving.
Open the bonnetthe in-depth explanation
How to check it
Check the per-cylinder misfire counters on your scanner to see which cylinder is affected. With the engine cold, swap that coil with one from another cylinder; if the fault moves with it, the coil is to blame.
How to read and clear P2306 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2306 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2302 There is a fault in the secondary circuit of ignition coil A
- P2303 Ignition coil B primary control circuit low
- P2304 Ignition coil B primary control circuit high
- P2305 There is a fault in the secondary circuit of ignition coil B
- P2307 Ignition coil C primary control circuit high
- P2308 The secondary circuit of ignition coil C has a fault
- P2309 The primary ignition coil D control gives a lower signal than normal
- P2310 The primary ignition coil D control gives a higher signal than normal
- P2300 Ignition coil A primary control circuit low
- P2301 Ignition coil A primary control circuit high
What does code P2306 mean?
The ECU fires each ignition coil by switching its primary circuit, the winding that carries the supply current. On coil C it has measured a voltage below the normal range, so it cannot drive the coil properly. Which cylinder coil C serves is set by each manufacturer.
Can you drive with P2306?
If the engine runs smoothly you can drive to a garage, but do not leave it long. If the warning light flashes or the engine shakes, a cylinder is misfiring and can damage the catalytic converter, so stop driving.
How do you clear P2306?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2306 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
