Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P050A Cold Start Idle Control System Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

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

Symptoms

  • Check engine light on
  • Idle after a cold start too low, too high or hunting
  • Occasional stalling shortly after a cold start

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–350
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

idle controlthrottle bodycold start strategyengine control module

Related codes

P050BP050EP0505P0506P0507P2111

References: law.cornell.edu, newtonnet.co.uk, roushcleantech.com.