Before Changing A Control Module

It has been found that the majority of control modules returned for repair under warranty are in perfect working order. In these cases, fitting a replacement control module has obviously not cured the fault. Therefore, go through the following points carefully before definitely deciding to change the control module:

1 Check all grounding points and the power supply for the control module.
2 Use the diagnostics instrument to check that all test readings obtained are plausible (several test readings may have a bearing on a particular function).
3 Use the diagnostics instrument to check that all activated functions are in working order (a fault in one output circuit could affect another output circuit).





4 If the fault persists the control module will have to be changed.
5 When handling control modules it is important to ground yourself first by touching the bonnet, for instance. Avoid touching the control module's pins.