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Reading out the fault memory of your car - Preston Tyre Bay!

Memory Sensors, gauges and other components of the vehicle constantly provide data to the controller to allow and verify smooth operation of the engine. If an error occurs in the calculated values, this enters the so-called fault memory.

Typically, the driver will be alerted about this error by an audible signal or by a warning symbol lighting up on the car's dashboard. To be able to interpret this error message, it must be read out via the control unit, the vehicle repaired if necessary and then deleted.

With us, you will learn how a fault memory works and what possible signs of a defect look like.

With us, you will learn how a fault memory works and what possible signs of a defect look like.

The operation of the fault memory

The fault memory stores technical defects and malfunctions in a motor vehicle. The fault memory is located in the so-called control unit and has an OBD interface (on-board diagnosis). Strictly speaking, in a vehicle, there is not just a general fault memory. Each control unit has such devices, so the diagnostic device will eventually receive error codes from a variety of modules.

For example, errors can clearly indicate engine problems, but not a defective cylinder head gasket (change cylinder head). Again, these errors can be based on different sources.

The components in the car, for example, measure the values of the lambda probe (change lambda probe), the speeds of various waves and the mass of the incoming air. The latter is used, for example, to calculate the ideal mixture for combustion in the engine.

When evaluating the errors, a distinction is made between static and sporadic errors. Static errors are stored long-term and do not disappear from the error memory. However, sporadic errors are eliminated if they only appear at certain intervals.

Therefore, after the occurrence of a fault, a car repair shop should be consulted immediately so that a misdiagnosis can be determined with certainty.

These signs indicate a possible defect:

As so often, there are several signs that can speak for a defect. Below is a selection of the most common symptoms:

  • Airbag lamp lights
  • The airbag lamp in the instrument cluster lights up.

  • ABS lamp lights
  • The ABS light in the instrument cluster lights up.

  • Battery warning light
  • The battery warning light in the instrument cluster lights up.

  • Engine Control Light
  • The engine indicator lamp (also referred to as engine warning lamp) in the instrument cluster lights up.

Reading the fault memory

Notes can be deleted again in the error memory. The mere reading out and interpretation of the error memory was greatly simplified by the introduction of the so-called OBD2 (On Board Diagnosis 2). Usually, a standardised plug is used to connect this to a socket of the control unit. Often this is located in the passenger compartment - especially in older models; it is also found in the engine compartment. When reading out the fault memory, it may happen that any disturbing elements - such as covers - have to be removed in advance. If the reader is linked to the error memory, the error codes can be read out.

Through existing tables, the errors can be identified by means of the number combinations. In addition, the error memory can also be deleted. It should be noted that not every vehicle is compatible with any diagnostic device or software. So it can be difficult, especially for exotic brands, to find a workshop with suitable software.

What you should look for in the error memory in your car:

Information is constantly sent to the controller to ensure smooth engine operation Usually, the driver will be alerted to this error by an audible signal or by a warning symbol lighting up Pay attention to possible defects (airbag lamp lights up, ABS lamp lights up) Have the readout carried out in our specialist workshop:

Engine Diagnostics - Preston Tyre Bay & Autocare in Preston.