Electrical System Diagnosis

Electrical System Diagnosis

The operation of the ANTI-LOCK warning lamp and BRAKE warning lamp are very important signs of electrical failure. If the ANTI-LOCK warning lamp is on without the BRAKE warning lamp, a failure is electrical in nature and can be easily diagnosed by removing the connector from the Anti-Lock Brake Control Module (ABCM) and connecting it to the MST-64OO TESTER. The following Symptoms Chart, Quick Test and (Fault Tree) Tables provide a logical path for the location of a fault.

While performing the electrical tests it is very important that a digital volt/ohm meter is used to insure the accuracy of the readings. First select the proper scale, and then carefully read each component through the pinout box on the MST-640Q. TESTER, then when a fault is found, move to the part and check it directly.

NOTE: when performing tests at the ABCM 35 pin connector, always use the pinout box on the MST-6400 tester. never probe the connector directly as damage may result.

It is important that while doing electrical checks that each plug is inspected visually for frayed wires or bent plug pins. When checking the harness side of a connector, carefully peel back the rubber boot and probe the plug from the back side.