Procedure Prior to Replacement

If it has not been possible to find any fault after everything has been checked in accordance with the diagnostic procedure for the relevant diagnostic trouble code, and separate checking of component operation has also been carried out, it is natural to assume that the control module is defective. In view of the fact that the control module is manufactured to extremely exacting standards of quality, and also because it is a rather expensive component, every effort should be made to ensure that diagnosis is as accurate as possible. Therefore, run through the following points before definitely settling on the TSAS control module as the cause of the fault.

1 Check once again that all points in the relevant diagnostic procedure have been carried out correctly.

2 Study the wiring diagram of the relevant circuit until you understand how it works.

3 Check the control module's ground connections once again and also check that the relevant grounding points are good and correct.

4 Check the control module's power supply.

5 Also run through the points in Description of on-Board Diagnostics and check that nothing has been forgotten or overlooked. Initial Inspection and Diagnostic Overview

6 If the original fault still persists, the TSAS control module will have to be changed.