P050A
- Powertrain
- Generic (SAE)
- Emissions
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
Cold Start Idle Control System Performance
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
During the cold-start phase the ECU runs an elevated idle speed and a richer mixture to bring the catalyst above light-off temperature quickly. The cold-start idle does not behave as commanded - speed sags, hunts, or fails to come up. Possible causes are intake leaks active when cold, an IAC valve sticking, or implausible coolant temperature.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- No
- Check engine light
- Solid
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Intake leak only when cold (gasket shrinks) | Very common | — |
| 2 | IAC valve sticking when cold | Common | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Idle Air Control Valve
- Cold Start Strategy
- Intake Manifold Seal
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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