Regal V6-3.8L VIN K (1997)
Body Control Module: Diagnostic Aids
Basic Knowledge Required
Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures. You should understand the basic theory of electricity and
know the meaning of voltage, current (amps) and resistance (ohms). You should understand what happens in a circuit with an open or a shorted wire.
You should be able to read and understand a wiring diagram.
The following four-step troubleshooting procedure is recommended:
Step 1: Check the Problem
Perform a System Check to determine a symptom. Don't waste time fixing part of the problem! Do not begin disassembly or testing until you have
narrowed down the possible causes.
Step 2: Read the Electrical Schematic
Study the schematic. Read the Circuit Operation text if you do not understand how the circuit should work. Check circuits that share wiring with
the problem circuit. (Shared circuits are shown on Power Distribution, Ground Distribution, Fuse Block Details and Light Switch Details.) Try to
operate the shared circuits. If the shared circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem
circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty.
Step 3: Find the fault and repair
Narrow down the possible causes.
Use the Troubleshooting Hints.
Make the necessary measurements or checks as given in the System Diagnosis.
Before replacing a component, check power, signal and ground wires at the component harness connector. If the checks and connections are
OK, the most probable cause is component failure.
Step 4: Test the Repair
Repeat the System Check to verify that the fault has been corrected and that no other faults were induced during the repair.
EXAMPLE: A customer brings in a vehicle and says that the HI beams do not work.
Step 1: Perform a System Check on the Headlight Circuit
You may discover that both LO beams operate. In HI, you may notice that the HI Beam Indicator comes ON, but neither HI beam operates.
Typical Headlights Schematic