After a cold start the engine module raises idle speed and air mass and retards the ignition so that much heat goes into the exhaust and the catalyst lights off quickly. CARB requires this cold-start strategy to be monitored with its own codes, separate from ordinary idle and ignition faults. Ford collects data during the first 15 s after a cold start (coolant and catalyst 20–100 °F) and judges after 300 s, once per trip. P050A checks whether the raised idle speed or air mass commanded at a cold start is actually reached: Ford sets it when the average deviation between target and actual speed exceeds 200 rpm, with the warning lamp. GM does not use P050A as its own monitor and reports cold-start system faults under its manufacturer code P1400.
Low severity. Can I keep driving?Yes, you can normally keep driving. If it stalls at intersections or traffic circles, avoid driving until it is repaired.
Symptoms
- Check engine light on
- Idle after a cold start too low, too high or hunting
- Occasional stalling shortly after a cold start
Most likely causes
- Throttle or idle valve dirty or coked, not enough air when cold
- False air or vacuum leak
- Fault in the throttle or idle valve circuit
- Extra load at cold start (alternator, A/C), stiff engine
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P050A means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 0A: Specific fault in that system
Frequently asked questions
Can I keep driving with code P050A?
Yes, you can normally keep driving. If it stalls at intersections or traffic circles, avoid driving until it is repaired.
What causes code P050A?
The most common causes are: throttle or idle valve dirty or coked, not enough air when cold; false air or vacuum leak; fault in the throttle or idle valve circuit.
Related codes
- P050BCold Start Ignition Timing Performance
- P050ECold Start Engine Exhaust Temperature Too Low
- P0505Idle Control System
- P0506Idle Control System RPM - Lower Than Expected
- P0507Idle Control System RPM - Higher Than Expected
- P2111Throttle Actuator A Control System - Stuck Open
Sources
- law.cornell.edu: 13 CCR 1968.2
- newtonnet.co.uk: fordobd2012
- roushcleantech.com: Roush CleanTech Diagnostics Manual DA 8.5.18
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.