Toyota Corolla Repair Manual: Symptom confirmation and diagnostic trouble code
Hint
:
- the diagnostic system in corolla has various functions. The first
function is the diagnostic trouble
code (dtc) check, in which a malfunction in the signal circuits to the ecu
is stored in code form in
the ecu memory. Another function is the input signal check, which checks if
the signals from various
switches are sent to the ecu correctly. By using these check functions, it
is possible to quickly narrow
down potential problem areas and troubleshooting can be performed
effectively. The diagnostic functions
are incorporated in the following systems in the corolla.
System |
Diagnostic trouble
code check |
Input signal check
(sensor check) |
Diagnostic test
mode (active test) |
Sfi system |
(With
check mode) |
|
|
Abs with ebd system |
|
|
|
Electronic controlled automatic transaxle [ect] |
(With
check mode) |
|
|
Supplemental restraint system |
|
|
|
Cruise control system |
|
|
|
- In the dtc check, it is very important to determine whether the
problem indicated by the dtc is still
occurring or has occurred in the past but returned to normal at present. In
addition during the problem
symptom check, it a check must be made on whether the malfunction indicated
by the dtc is directly
related to the problem symptom or not. For this reason, the dtc should be
checked before and after
symptom confirmation to determine the current conditions. If this is not
done, it may, depending on the
case, result in unnecessary troubleshooting for systems that are operating
normally. This would make
more difficult to detect the problem area or to try to repair irrelevant
areas. Therefore, always follow
the procedures in the correct order and perform the dtc check.
- A flow chart showing how to proceed with troubleshooting using the
diagnostic trouble code (dtc)
check is shown the this page. This flow chart shows how to utilize the dtc
check effectively. Then,
by carefully checking the results, this chart indicates how to proceed
either to the dtc troubleshooting
or to the troubleshooting of the problem symptoms table.
1 Dtc check
2 Making a note and clear the dtcs
3 Symptom confirmation
|
Problem symptoms exist |
|
No problem symptoms exist |
A go to step 5
B
4 Simulation test using the symptom simulation methods
5 Dtc check
|
Dtc displayed |
|
Normal code displayed |
A troubleshooting of problem indicated by dtc
B
6 Symptom confirmation
|
No problem symptoms exist |
|
Problem symptoms exist |
If a dtc is displayed in the initial dtc check, it indicates that
a trouble may have occurred in a wire harness or connector in
that circuit in the past, therefore check the wire harness and
connectors .
A system normal
B
Troubleshooting of each problem symptom
The problem is still occurring in a place other than the diagnostic circuit
(the dtc displayed first is either
for a past problem or it is a secondary problem).
Hint:
in troubleshooting, the problem symptoms must be confirmed
accurately, meaning that all preconceptions
must be set aside in order to make an accurate judgement. To ascertain what
the ...
Hint:
the most difficult case in troubleshooting is when no symptoms occurs. In such
cases, a thorough customer
problem analysis must be carried out. Then the same or similar conditions and
envi ...
Other materials:
Inspection procedure
1 Check tvip ecu
Check that the operation of the tvip function is normal.
Hint:
with this inspection, the tvip ecu cpu can be diagnosed if it works normally or
not.
2 Check wire harness (tvip ecu integration relay)
Disconnect the tvip ecu and integration relay connectors.
ch ...
Steering column
Preparation
Sst
Recomended tools
Equipment
...
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove front door scuff plate rh
4. Remove rear door scuff plate rh
5. Remove front door opening trim rh
6. Remove rear door opening trim rh
7. Remove lap belt outer anchor cover
8. Remove center pillar garnis ...