Diagnostic Information

The Electrical Diagnosis section contains the following types of diagnostic information (the way in which the information is arranged may vary from system to system or vehicle to vehicle:
- Electrical Schematics.
- Component Location Lists.
- Harness Connector Faces.
- Troubleshooting Hints.
- System Checks.
- System Diagnosis.
- Circuit Operation Descriptions.
- Harness Routing Views.

Using these elements together will make electrical troubleshooting faster and easier. Each element is described below.

The Circuit Schematic shows the electrical current paths when a circuit is operating properly. It is essential to understand how a circuit should work before trying to diagnose a failure.

The Component Location List helps to find where the components of a system can be located. A brief statement of the location is given and also a reference to a drawing that shows the component and its connecting wires.

The Harness Connector Faces show the cavity or terminal locations in all the 4 pin or larger connectors shown in the schematic. Together with the wire colors and terminals given in the schematic, they help locate test points. The drawings show the connector faces as seen after the harness connector has been disconnected from a component or mating connector.

The Troubleshooting Hints offer shortcuts or checks to help determine the cause of a complaint. They are not intended to be a rigid procedure for solving an electrical situation. Rather, Troubleshooting Hints represent a common sense approach, based on an understanding of the circuit.

The System Check gives a summary of how the system should be operated and what should happen. This is especially important when working on a new system. The System Check will help identify symptoms, lead to diagnosis and confirm normal operation of the system after repair.

The System Diagnosis provides a procedure to follow that will locate the condition in a circuit causing a malfunction. If your own knowledge of the system and the Troubleshooting Hints have not produced a quick fix, follow the System Diagnosis. All procedures are based on symptoms to assist in locating the condition as fast as possible.

The Circuit Operation describes the components and how the circuit works.

The Harness Routing Views show the routing of the major wiring harnesses and the in-line connectors between the major harnesses.