P21A5 Trouble Code

View P21A5 obd/2 error code description and symptoms. P21A5 engine photo

Catalytic converters must be warm before they can work properly. On a cold start the PCM provides a rich mixture to keep the cold engine running.
All that extra fuel goes into the catalytic converter. But the exhaust isn't very hot, because, ah, the engine is pretty cold. GM has employed several strategies to fire up the catalytic converter quicker and reduce cold start emissions. One way is to use a secondary air pump that pumps outside air directly into the catalytic converter.

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair. For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.

Difficulty Level (Easy)
Level
Repair Time (20 Min.)
Time
Cost Prediction : $ 30-110

P21A5 Error Code Repair Process :

When you turn on the ignition, the Service Engine Soon or Check Engine P21A5 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If camshaft position sensor b circuit malfunction so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the camshaft position sensor b circuit malfunction.

Wrench Tool P21A5 is a kind of Powertrain Trouble Code

Powertrain of a modern automobile, comprising engine (with exhaust system), transmission, drive shaft, suspension and the wheels. In a motor vehicle, the term powertrain or powerplant describes the main components that generate power and deliver it to the road surface, water, or air.

Common Causes of P21A5

A common cause of code P21A5 is the failure of Camshaft Position Sensor B Circuit Malfunction, but there are several other possible causes as well, such as ;

P21A5 code for all cars

You can view according P21A5 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+P21A5 Plymouth Breeze +P21A5 Proton 400 +P21A5 Ferrari F40 +P21A5 De Dion Bouton 18 +P21A5 Toyota Ractis

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