Audi A4: P0720 → OSS Circuit → Malfunction

P0720 is a generic OBD II trouble code, which means that it has the same meaning for your Audi A4 as it would any other vehicle.  It indicates that your A4’s OSS (Output Shaft Speed Sensor) is reporting a malfunction. It’s typically caused by a bad OSS, or a wiring problem. The OSS works by … Read more

Audi A4 P0520: Oil Pressure Switch/Sensor → Circuit

  P0520 is a common OBD2 trouble code.  It’s generic, which means that it has the same meaning for the Audi A4 as it would any other vehicle.  P0520 indicates that the oil pressure sensor is operating outside of its normal “range”.  It is typically caused by a bad oil pressure sensor switch or a … Read more

Audi A4 P0108:  MAP Barometric Sensor → High Input 

  P0108 is a generic OBD-II trouble code.  It indicates your Audi A4’s MAP (manifold absolute pressure) sensor’s voltage reading is outside of the normal operating range.  The voltage is too high.  It’s most commonly caused by a bad MAP sensor, wiring issue, or vacuum leak. The MAP sensor measures the air pressure coming into … Read more

Audi A4 P0443 Code: Meaning, Causes, How To Fix

P0443 is a very common OBD2 code.  It’s generic, meaning it has the same definition for the Audi A4 as any other vehicle.   If your A4 has this code, it indicates the EVAP purge control valve circuit is malfunctioning. This is typically caused by a short in the wiring to or from the purge … Read more

Audi A4 P0521: Oil Pressure Sensor Switch → Performance/Range

P0521 is an OBD2 diagnostic code that is triggered when your Audi A4 detects that the value being sent from the oil pressure sensor is out of its normal operating range. It is typically caused by a bad oil pressure sensor or an issue with the oil system, and should be diagnosed and fixed right … Read more

Audi A4: P0562 – System Voltage Low

P0562 is a common OBD-II trouble code.  It’s a general code, which means that it means the same thing for any vehicle, including the Audi A4.  P0562 indicates that the system voltage is below 10 volts for a solid minute.  With the engine running, the system voltage should be 14.1-14.4 volts, and it’s typically caused … Read more

Audi A4:  Signs of a Bad Water Pump

Your Audi A4’s water pump is one of the most crucial parts of the engine.  If it doesn’t pump water through the engine, it’s going to overheat and do a lot of damage.  Typical signs of a bad water pump include overheating, white smoke, a bad smell, rough idle, and more. A water pump works … Read more

Audi A4: Running Hot → Causes

If your Audi A4 is running hot, it is a serious problem.  If it gets too hot, it leads to overheating.  A hot engine is usually caused by a few different things, such as the thermostat, water pump, radiator, or outside conditions.     Audi A4 Running Hot Symptoms Obviously, the main symptom of running … Read more

Audi A4 Rod Knocking Diagnosis

A rod knock is a very serious problem.  If your Audi A4 has a knocking rod, it’s almost always going to be caused by a failure of the rod bearing or the rod caps (leading to a spun bearing) or lack of oil.   If you do have a rod knock, don’t ignore it for … Read more

Audi A4: Bad Torque Converter → Symptoms + Diagnosis

Your Audi A4’s torque converter is responsible for converting the energy generated by the engine at the flywheel and transferring it to the transmission, creating a bridge between the engine and the transmission.   In the Audi A4, a bad torque converter is often caused by bad transmission fluid, worn clutches, bad seals, or loose … Read more