Erratic behaviour in an electronic control device


The GM Consultant analysis and electronic investigations laboratory was ordered to study the electronic assembly, observe and verify operation under actual conditions, and issue a decision regarding a possible hidden defect in one of the electronic components of the assembly.


A study of the assembly diagram showed non-standard use of two voltages in an assembly with a microprocessor and unsuitable management of the phases for turning power to the assembly on and off.

These elements could lead to memorised operational data becoming lost or randomly corrupt.

The assembly was observed in operation at the electronic laboratory and measured using an oscilloscope.

The measurements confirmed the haphazard operation and the possible loss of data. Certain electronic signals were not compliant with the technical specifications of the microprocessor manufacturer.

The hypothesis of a hidden defect in the microprocessor was eliminated. Likewise, the corrective solution suggested by the manufacturer of the control device was considered inappropriate for resolving the issue even before it was implemented, thus preventing a second incident or even greater damage.