Before beginning diagnosis on the ABS/TCS system, obtain a detailed description of when the condition occurred or occurs from the owner. This information may be useful in duplicating the condition. Perform a quick visual check of all connectors, wiring, wire routing and retention, and system components. Many times a disconnected or loose connector, open fuse, or misrouted wire can be the cause of a problem.

If a visual inspection does not reveal an obvious problem, ALWAYS start with the Diagnostic System Check table. This step is critical in quick and accurate diagnosis of any problem. Correct system diagnosis cannot be ensured without starting diagnosis with the Diagnostic System Check.