M2/M3 BFV: TROUBLESHOOTING - OD1610 - LESSON 1/TASK 1
Once the problem has been narrowed down, it's time to isolate the problem to
the component that is defective.
Since the first component in the fuel
system after the gas tank is the fuel pump, that is where you will begin.
After performing a visual inspection of the fuel pump and certain diagnostic
tests, you come to the conclusion that the fuel pump is not the problem.
The next component is the fuel filter. This is a likely candidate because
they go bad more often than fuel pumps, and also because they should be
replaced every so many thousand miles (and this one has not been). After
visually inspecting the filter and performing a couple of diagnostic tests,
you arrive at the conclusion that the fuel filter is bad.
You have just
completed the first two steps in the troubleshooting process; namely,
verifying that the malfunction exists and actually troubleshooting the
(3) Replace or Adjust the Part. The next step in the troubleshooting
process is to actually correct the malfunction. This can be done in one of
two ways: first, adjust the faulty component (provided it is adjustable);
second, replace the component. Most of the time the component will simply
be replaced as unit level maintenance is not usually authorized to adjust
To illustrate this better, let's return to the scenario that we have been
following. You have isolated the problem to the fuel filter. To correct
this malfunction, the fuel filter should either be adjusted or replaced.
Since it is impossible to adjust a fuel filter, the filter will be replaced.
(4) Verify the Correction of the Problem.
The final step in the
troubleshooting procedure is to verify that the problem has been corrected
and that no other problems exist. This is done by first re-performing the
If, at the end of the troubleshooting
procedures, it is determined that no faults were found, operate the
equipment to make sure that nothing else is wrong.
Let's finish up our scenario.
you have tested it to make sure that the installation was correct. Now test
drive the car to make sure that the problem has