P050D
Cold Start Rough Idle
Idle / cold-start control
Generic OBD-II
High
What it means
P050D means the ECM detected an unusually rough or unstable idle during a cold start. On a cold engine the mixture and idle speed are more sensitive, so a vacuum leak, dirty throttle body, weak ignition, or a skewed sensor reading shows up as shaking or stumbling that typically smooths out once the engine warms up.
High
Can I keep driving? Usually drivable — the roughness is mostly during the first minutes after a cold start and smooths out as the engine warms, but it can stumble or stall cold until fixed.
Common symptoms
What you'll notice
- Rough or unstable idle right after a cold start
- Engine may shake, stumble, or briefly stall when cold
- Idle smooths out as the engine warms up
- Check-engine light on
Common causes
Most likely first
- Vacuum or intake air leakLikely
- Dirty throttle body or carboned intake valvesCommon
- Failing ignition components (plugs, coils)Common
- Leaking or clogged fuel injectors / low cold-start fuel pressureLess often
- Faulty coolant-temp or MAF sensor skewing the cold fuel mixtureLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the code with a scan tool.
- Check for vacuum/intake air leaks and clean the throttle body.
- Inspect spark plugs and ignition coils for wear or misfire.
- Verify cold-start fuel pressure and injector operation.
- Test the coolant-temp and MAF sensors that set the cold mixture. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P050D?+
Usually yes — the roughness is mostly a cold-start condition that clears as the engine warms. If it stalls repeatedly when cold, get it fixed before it strands you.
Can I just clear P050D?+
It returns on the next cold start until the underlying idle or mixture problem is corrected. Clearing only resets the light.
Related codes
Often seen with P050D
Read & clear P050D yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX