Troubleshooting - How to Read Flowcharts
6-20prose procedureHow to Read Flowcharts
A flowchart is designed to be used from start to final repair. It's like a map showing you the shortest distance. But beware: if you go off the "map" anywhere but a "stop" symbol, you can easily get lost.
START (bold type)
MeaningDescribes the conditions or situation to start a troubleshooting flowchart.
ACTION
MeaningAsks you to do something: perform a test, set up a condition, etc.
DECISION
MeaningAsks you about the result of an action by giving an "answer" and asking did you get the same answer: Yes or No.
STOP (bold type)
MeaningThe end of a series of actions and decisions, describes a final repair action and sometimes directs you to an earlier part of the flow to confirm your repair.
NOTE
The term "Intermittent Failure" is used several times in these charts. It simply means a system may have had a failure, but it checks out OK through all your tests. You may need to road test the car to reproduce the failure or if the problem was a loose connection, you may have unknowingly solved it while doing the tests.
"Open" and "Short" are common electrical terms. An open is a break in a wire or at a connection. A short is an accidental connection of a wire to ground. In simple electronics, this usually means something won't work at all. In complex electronics (like ECUs), this can sometimes mean something works, but not the way it's supposed to.
If the electrical readings are not as specified when using the PGM-FI test harness, check the test harness connections before proceeding.