One of the most common issues we get from technicians, is that they think too deeply about the issue, before doing the basic checks. A recent call to the Autobiz Helpline brings this to our attention.

A 2018 Mercedes GLA 1.6 petrol was brought into a member’s garage. The symptoms described by the customer, were a hesitation under acceleration in second and third gear. The fault read in the ECU was the soot content in the Gasoline particle filter (GPF) was too high. The scan tool gave the option to regenerate the GPF, which the technician completed.

As they had not seen a GPF before, they called the Autobiz Helpline for advice. We explained that the GPF was like a diesel particle filter (DPF), and was fitted to capture the carbon particles left over from incomplete combustion in petrol engine vehicles.

This fault was probably due to poor or incomplete combustion. Before you go off looking for complex diagnostic issues, you must think of the simple solutions first. Check the basics.

Look into the service history. Has the vehicle been maintained correctly, at the correct intervals?
What is the condition of the engine, and what are the relative compression figures? These can be quickly checked with Pico Diagnostics, by performing a non-invasive relative compression test. This test can save valuable time in confirming mechanical health.

As there were no fault codes present, we started by checking the spark plugs. This was all that was needed. The problem was a faulty spark plug, and as the service history confirmed, the plugs were due for replacement.

A seemingly complex issue, was just a spark plug failure. A service item that was close to its replacement interval.

An important beginning to an efficient process is to keep it simple, before looking into a complex diagnostic process.

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