Rough Idle at Cold Start? How to Diagnose Codes P050D and P219A

You start your car with the engine cold and get a rough idle and a check engine light for codes P050D and P219A. Why does this happen? This article and video explain what codes P050D and P219A mean and how you can fix a rough idle at cold start problem.

Fix Trouble Codes P050D and P219A

What Does Code P050D Mean?

Advanced scan tool reading for codes P050D, P219A, and P0300

Code P050D, defined as “cold start rough idle,” appears for a cold start at rough idle, which means when you start the vehicle and the engine is cold and hasn’t warmed up yet, the engine runs rough and feels shaky. The most common cause for a rough idle is a misfire, and this code may be accompanied by a P0300 cylinder misfire code.

What Does Code P219A Mean?

Code P219A, defined as “fuel trim cylinder balance bank 1,” appears for a problem with the fuel delivery system. A V8 engine has two banks, and this code means there is too much or too little fuel and the computer noticed.

Fix codes P050D and P219A yourself with quality auto parts at

Common Issues for Codes P219A and P050D

Tip: Codes P219A and P050D could be appearing for one of these problems or these problems could be related

Carbon Build Up on the Valves

Carbon can build up on the valves and cause a cold start misfire. This means the engine will need a top engine clean/decarbonization, which includes adding decarbonization cleaner to the top of the engine and letting it soak, burning the decarb cleaner off with the vehicle at idle, and driving the vehicle to remove more carbon from the engine.

Read here to learn more about decarbing your engine

Fuel Injector Failure

A common cause of code P219A is failed fuel injectors.

You can test to see if the problem is something else like a misfire before trying to fix for one of the causes above.

How to Test for Codes P219A and P050D

Steps for Testing Codes P219A and P050D

  1. Scan Test the Vehicle and Look for Misfires

    Scan test the vehicle with an advanced scan tool and look at the misfire counts. See if any are occurring as the engine warms up. If there is a code for a misfire in a specific cylinder, see if that or any cylinders specifically are misfiring. Rev the engine and see if you can get a misfire in that cylinder.

  2. Swap the Ignition Coils and Spark Plug Wires

    If the misfiring cylinder is on bank 1, it may be related to code P219A. You can swap the ignition coil and spark plug wires and see if the misfire follows the coil or the wires. If the misfire follows one, you will know that part is defective.

    If the misfire stays in the same cylinder after the coils and wires have been moved, there are no problems with the ignition system but there is one with carbon build up or the fuel injectors.

  3. Swap the Fuel Injectors

    You can swap the fuel injectors. If the misfire follows the fuel injectors, they need to be replaced.

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Rough Idle at Cold Start? How to Diagnose Codes P050D and P219A - 1A Auto
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Rough Idle at Cold Start? How to Diagnose Codes P050D and P219A - 1A Auto
If you have a cold start misfire and a check engine light for codes P050D and P219A, this guide explains what might be the cause and how to fix it.
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