Important Preliminary Inspections Before Starting
Before using the Symptom diagnosis, perform the following:
Perform Diagnostic System Check - Vehicle and verify all of the
following items:
Engine control module (ECM) and malfunction indicator lamp (MIL) are
operating correctly.
There are
The vehicle has fuses and circuit
breakers to protect against an
electrical system overload.
When the current electrical load is
too heavy, the circuit breaker opens
and closes, protecting the circuit
until the current load returns to
normal or the problem is fixed. This
greatly reduces the chance