P2305Ignition Coil B Secondary Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2305 is about coil B's output side: the secondary winding, the connection to the plug and the spark plug of cylinder 2. Where a maker uses it, the module does not just watch whether the coil was switched, but whether a usable spark happened. Ion sensing is one way: as with Saab's Direct Ignition, a low voltage is applied across the plug outside the firing moment, and the resulting ion current tells the module whether the mixture burned – it can even replace the knock sensor. FCA names P2305 coil 2 secondary circuit with insufficient ionization on 2015–2016 Caravan and Town & Country 3.6 V6 and listed it with P0300–P0306 when misfire, rough running and the MIL called for a new PCM. Unlike P2303/P2304, a clean control line does not rule this code out; spark plugs and boots come first.
- What you may notice
- Check engine light on
- Misfire on cylinder 2, sometimes only under load
- Rough running, raised fuel consumption
- Likely causes
- LikelySpark plug of cylinder 2 worn, oily or with the wrong gap
- PossibleCoil B boot cracked or damp, spark leaking away
- PossibleCoil B secondary winding weak
- RareFaulty ion-current evaluation in the PCM
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.