Checking the Basics

When all tests have been carried out according to the relevant diagnostics procedure or the various functions have been checked separately without any faults having been found, it is natural to assume that the control module is at fault.

In view of the fact that the control module is an exceptionally high-quality component and also extremely expensive, it is important to verify the diagnosis as far as possible.

Therefore, go through all the points very carefully before definitely pointing to the control module as the cause of the fault.





1 Check once again that every single point in the relevant diagnostic procedure has been carried out correctly and conscientiously.

2 Study the wiring diagram of the circuit in question and make sure you understand how it works.

3 Check all control module grounding connections once again and check that all grounding points are correctly grounded.

4 Check the voltage supplied to the control module.

5 If the original fault still persists in spite of this, the control module will have to be changed.