Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P050A: Cold Start Idle Control System Performance: Notes
DTC detecting condition:
Detected when two consecutive driving cycles with fault occur.
Trouble symptom:
- Engine keeps running at higher speed than specified idle speed.
- Engine keeps running at a lower speed than the specified idle speed.
- Engine stalls.CAUTION:
- After servicing or replacing faulty parts, perform Clear Memory Mode Refer to ENGINE (DIAGNOSTICS) (W/O STI)>CLEAR MEMORY MODE>OPERATION ., and inspection mode Refer to ENGINE (DIAGNOSTICS) (W/O STI)>INSPECTION MODE>PROCEDURE .
- Use the check board when measuring the ECM terminal voltage and resistance.
Wiring diagram:
Engine Electrical System Refer to WIRING SYSTEM>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- CHECK DTC.
Read the engine DTC using the Subaru Select Monitor or general scan tool. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>READ DIAGNOSTIC TROUBLE CODE (DTC) .
Is other than DTC P050A displayed? (Current malfunction)
Yes: Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to ENGINE (DIAGNOSTICS) (W/O STI)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .
No: Go to 2.
- CHECK ENGINE OIL.
Check the engine oil.
Is there a proper amount of engine oil?
Yes: Go to 3.
No: Replace engine oil. Refer to LUBRICATION(W/O STI)>ENGINE OIL>REPLACEMENT .
- CHECK EXHAUST SYSTEM.
Check the exhaust system.
Are there holes or loose bolts on exhaust system?
Yes: Repair the exhaust system.
No: Go to 4.
- CHECK AIR INTAKE SYSTEM.
Check the air intake system.
Are there holes, loose bolts or disconnection of hose on air intake system?
Yes: Repair the air intake system.
No: Go to 5.
- CHECK FUEL PRESSURE. WARNING: Place "NO OPEN FLAMES" signs near the working area.
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.