2015 Buick P0300: What It Means & Is It Safe to Drive?
P0300 on the 2015 Buick: Random/Multiple Cylinder Misfire Detected. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
The PCM has detected misfires across multiple cylinders. This can cause damage to the catalytic converter if driven for long.
Common causes on the 2015 Buick
- Worn spark plugs or ignition coils
- Clogged or bad fuel injectors
- Low compression
- Vacuum leak, bad MAF, or fuel delivery issue
Symptoms
- Check Engine Light (often flashing under load)
- Rough idle, shaking, loss of power
- Possible smell of unburned fuel
Typical fixes
- Replace spark plugs and coils as needed
- Clean or replace fuel injectors
- Fix vacuum/fuel issues
- Compression test if no obvious cause
Repair cost range
For a 2015 Buick, repairs for P0300 typically fall between $150 and $1200, depending on the root cause and labor rates in your area.
Known issues on Buick
Buick P0300 on 3.6L LFX V6 (Enclave, LaCrosse) can result from a failed ignition coil or a timing chain stretch issue known to affect LLT and LFX engines. The timing chain tensioner failure is a common complaint—look for a rattling noise on cold start alongside P0300.
Most commonly affected models
LaCrosse 2010–2016Enclave 2008–2017Verano 2012–2017