Specifications

TROUBLESHOOTING GUIDELINES
TSB Revision
GENERAL
00-6
TROUBLESHOOTING GUIDELINES
M1001008800287
VERIFY THE COMPLAINT
• Make sure the customer's complaint and the ser-
vice writer's work order description are under-
stood before starting work.
• Make sure the correct operation of the system is
understood. Read the service manual description
to verify normal system operation.
• Operate the system to see the symptoms. Look
for other symptoms that were not reported by the
customer, or on the work order, that may be
related to the problem.
DETERMINE POSSIBLE CAUSES
Compare the confirmed symptoms to the diagnostic
symptom indexes to find the right diagnosis proce
-
dure.
If the confirmed symptoms cannot be found on any
symptom index, determine other possible causes.
• Analyze the system diagrams and list all possible
causes for the problem symptoms.
• Rank all these possible causes in order of proba-
bility, based on how much of the system they
cover, how likely they are to be the cause, and
how easy they will be to check. Be sure to take
experience into account. Consider the causes of
similar problems seen in the past. The list of
causes should be ranked in order from general to
specific, from most-likely to least-likely, and from
easy-to-check to hard-to-check.
FIND THE PROBLEM
After the symptoms have been confirmed, and prob-
able causes have been identified, the next step is to
make step-by-step checks of the suspected system
components, junctions, and links in logical order.
Use the diagnostic procedures in the service manual
whenever possible. Follow these procedures care
-
fully to avoid missing an important step in the diagno-
sis sequence. It might be the skipped step that leads
to the solution of the problem.
If the service manual doesn't have step-by-step pro-
cedures to help diagnose the problem, make a series
of checks based on the ranked list of probable
causes. Troubleshooting checks should be made in
the order that the list of causes was ranked:
• general to specific
• most-likely to least-likely
• easy-to-check to hard-to-check
REPAIR THE PROBLEM
When the step-by-step troubleshooting checks find a
fault, perform the proper repairs. Make sure to fix the
root cause of the problem, not just the symptom. Just
fixing the symptom, without fixing the root cause, will
cause the symptom to eventually return.
VERIFY THE REPAIR
After repairs are made, recheck the operation of the
system to confirm that the problem is eliminated. Be
sure to check the system thoroughly. Sometimes
new problems are revealed after repairs have been
made.
HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE
POINTS
TROUBLESHOOTING CONTENTS
M1001013300103
Troubleshooting of electronic control systems for
which the scan tool can be used follows the basic
outline described below. Even in systems for which
the scan tool cannot be used, part of these systems
still follow this outline.
1. STANDARD FLOW OF DIAGNOSTIC
TROUBLESHOOTING
Troubleshooting strategy is shown in each group.
2. SYSTEM OPERATION AND SYMPTOM
VERIFICATION TESTS
If verification of the symptom(s) is difficult, proce-
dures for checking operation and verifying symptoms
are shown.
3. DIAGNOSTIC FUNCTION
The following trouble code diagnosis are shown.
• How to read diagnostic trouble codes
• How to erase diagnostic trouble codes
• Input inspection service points