What does a p050d cold start rough idle mean?
So, you are faced with diagnosing a stored a code P050D. It means that the powertrain control module (PCM) has detected a rough engine idle during cold start. Cold start is a term used to describe an engine drivability strategy that is implemented only when the engine is at (or below) ambient temperature.
What causes a rough idle during a cold start?
If fuel pressure is low, check the fuel filter for obstruction. An ignition misfire will also create a rough idle at cold start. Misfire is a lot more likely to occur after the engine reaches normal operating temperature but I have witnessed cases in which a misfire could only be detected during cold start conditions.
How does cold start work on an engine?
Cold start is a term used to describe an engine drivability strategy that is implemented only when the engine is at (or below) ambient temperature. Engine RPM is monitored (by the PCM) using data input signal voltage from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor. The idle RPM level is also controlled by the PCM.
How can you tell when your car is having a rough idle?
You can tell your vehicle is having a rough idle when cold if there is shaking and bouncing sensation in the vehicle, and you feel like the car is vibrating too much while your car is not moving. Although some cases are less severe than others, the rough idle is usually pretty identifiable by both the driver and passengers.
If fuel pressure is low, check the fuel filter for obstruction. An ignition misfire will also create a rough idle at cold start. Misfire is a lot more likely to occur after the engine reaches normal operating temperature but I have witnessed cases in which a misfire could only be detected during cold start conditions.
So, you are faced with diagnosing a stored a code P050D. It means that the powertrain control module (PCM) has detected a rough engine idle during cold start. Cold start is a term used to describe an engine drivability strategy that is implemented only when the engine is at (or below) ambient temperature.
Cold start is a term used to describe an engine drivability strategy that is implemented only when the engine is at (or below) ambient temperature. Engine RPM is monitored (by the PCM) using data input signal voltage from the crankshaft position (CKP) sensor and the camshaft position (CMP) sensor. The idle RPM level is also controlled by the PCM.
Can a misfire occur during a cold start?
Misfire is a lot more likely to occur after the engine reaches normal operating temperature but I have witnessed cases in which a misfire could only be detected during cold start conditions. Check spark plugs, spark plug boots, and ignition coils for signs of oil or water/coolant contamination.