Operation CHARM: Car repair manuals for everyone.

Checking the Basics


DIAGNOSTIC NOTES
Diagnosing problems in modern automobiles can sometimes be very frustrating and confusing, especially when it involves computer controlled systems. The fact is, for the most part automotive electronics have been proven quite reliable, and the greatest number of problems with new cars are the same kinds of problems that older cars without computer controls have.

Before beginning diagnosis on the Rear Wheel Anti Lock (RWAL)system, you need a detailed description of when the condition occurred from the owner. This information can be useful in duplicating the condition.

Begin all troubleshooting by Checking the Basics. Before suspecting a computer problem, perform a careful visual brake inspection.

Perform a visual inspection of all connectors, wiring, wire routing and retention, and system components. Many times a disconnected or loose connector, blown fuse, corroded terminal, or miss-routed wire is the cause of a malfunction.

INTERMITTENTS AND POOR CONNECTIONS
Most intermittent faults are caused by a faulty electrical connection or wiring, although a sticking relay or solenoid can occasionally be at fault. Refer to Diagnostic Aids. Diagnostic Aids

WIRING AND CONNECTOR REPAIR
The wiring and connector repair is very important for the continued reliable operation of the vehicle. Refer to Diagnostic Aids. Diagnostic Aids

If a visual inspection does not reveal the cause of a malfunction, perform the Functional Test.

This is a critical step in the quick and accurate diagnosis of any malfunction. It will direct you to the specific system area that is malfunctioning and verify that the diagnostic system is functioning properly. Correct system diagnosis cannot be ensured without starting diagnosis with the Functional Test.