C20A4 Audi 80 OBD Code

OBD/2 C20A4 error code description and symptoms.

The Camshaft Position sensor will signal the Engine Control Module when the #1 cylinder is ready for the spark plug to fire (top-dead-center on compression stroke). The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

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.

C20A4 Audi 80 Error Code Repair Process :

If your vehicle failed a C20A4 test and the C20A4 Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses manifold absolute temperature circuit high input a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look manifold absolute temperature circuit high input: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression. Use your OBD Express DIY to look at the oxygen sensor outputs, coolant temperature, airflow, calculated engine load, and inlet air temperature.

Common Causes of Audi 80 C20A4 OBD2 Code

A common cause of code C20A4 is the failure of Manifold Absolute Temperature Circuit High Input, but there are several other possible causes as well, such as ;

Clogged or faulty fuel injector (s)
Faulty starter motor
Incorrect Positive Crankcase Ventilation (PCV) hose connection
Variable Camshaft Timing (VCT) position circuit is open or shorted

C20A4 is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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C20A4 Audi 80 OBD Code

C20A4 Audi 80 Error Code Repair Process :

Common Causes of Audi 80 C20A4 OBD2 Code

C20A4 code for other Audi cars