OBD-II code · Powertrain (generic, extended)
P2304 Ignition Coil B Primary Control Circuit High
Voltage on the primary control of ignition coil B exceeds the calibrated upper limit, indicating an electrical fault that prevents proper coil charging.
Is it safe to drive with P2304?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyPrimary wire shorted to battery
- PossibleOpen primary winding
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.2–1 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Ignition Coil, Coil Driver, Ignition Wiring
Related codes
- P2301Ignition Coil A Primary Control Circuit High
- P2307Ignition Coil C Primary Control Circuit High
- P2310Ignition Coil D Primary Control Circuit High
- P2313Ignition Coil E Primary Control Circuit High
- P2316Ignition Coil F Primary Control Circuit High
- P2319Ignition Coil G Primary Control Circuit High
- P2322Ignition Coil H Primary Control Circuit High
- P2325Ignition Coil I Primary Control Circuit High
- P2328Ignition Coil J Primary Control Circuit High
- P2331Ignition Coil K Primary Control Circuit High
- P2334Ignition Coil L Primary Control Circuit High
- P2302Ignition Coil A Secondary Circuit
- P2303Ignition Coil B Primary Control Circuit Low
- P2305Ignition Coil B Secondary Circuit
- P2306Ignition Coil C Primary Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.