Diagnostic Trouble Code Check Procedure - Toyota Tundra 2005 Service - Repair - Maintenance

IN−22
In the DTC Check, it is very important to determine whether the problem indicated by the DTC is: 1) still occur-
ring, or 2) occurred in the past but has since returned to normal. In addition, the DTC should be compared
to the problem symptom to see if they are related. For this reason, DTCs should be checked before and after
confirmation of symptoms (i.e., whether or not problem symptoms exist) to determine current conditions, as
shown in the table below.
Never skip the DTC Check. Failure to check DTCs may, depending on the case, result in unnecessary trou-
bleshooting for systems operating normally or lead to repairs not pertinent to the problem. Follow the proce-
dures listed above in the correct order.

DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE

Diagnostic Trouble
Code Check (Make a
note of and then clear)
Diagnostic Trouble
Code Display
Normal Code Display
INTRODUCTION
Confirmation Diagnostic Trouble
of Symptoms Code Check
Problem symptoms Same diagnostic
exist trouble code is
displayed
Normal code is
displayed
No problem
symptoms exist
Problem symptoms Normal code is
exist displayed
No problem Normal code is
symptoms exist displayed
− HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
Problem is still occurring in the diagnostic
circuit
The problem is still occurring in a place
other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)
The problem occurred in the diagnostic
circuit in the past
The problem is still occurring in a place
other than the diagnostic circuit
The problem occurred in a place other
than the diagnostic circuit in the past
Problem Condition