Toyota RAV4 Service Manual: Symptom confirmation and diagnostic trouble code
Hint:
The diagnostic system in the rav4 has various functions.
- The first function is the diagnostic trouble code (dtc) check. A dtc is a code stored in the ecu memory whenever a malfunction in the signal circuits to the ecu occurs. In a dtc check, a previous malfunction's dtc can be checked by a technician during troubleshooting.
- Another function is the input signal check, which
checks if the signals from various switches are sent to
the ecu correctly.
By using these functions, the problem areas can be narrowed down and troubleshooting is more effective.
Diagnostic functions are incorporated in the following system in the rav4.
- In the dtc check, it is very important to determine whether the problem indicated by the dtc is either: 1) still occurring, 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 system conditions, as shown in the flowchart below.
- Never skip the dtc check. Failing to check dtcs may, depending on the case, result in unnecessary troubleshooting for systems operating normally or lead to repairs not related to the problem. Follow the procedures listed in the flowchart in the correct order.
- The following flowchart shows how to proceed with troubleshooting using the dtc check. Directions from the flowchart will indicate how to proceed either to dtc troubleshooting or to the 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 a secondary problem).
Customer problem analysis
Hint:
In troubleshooting, confirm that the problem symptoms
have been accurately identified. Preconceptions should be
discarded in order to make an accurate judgment. To
clearly understand w ...
Symptom simulation
Hint:
The most difficult case in troubleshooting is when no
problem symptoms occur. In such a case, a thorough
problem analysis must be carried out. A simulation of the
same or similar conditions ...
Other materials:
How to proceed with troubleshooting
Hint:
Perform troubleshooting in accordance with the following
flowchart.
*: Use the intelligent tester.
Vehicle brought to workshop
Inspect battery voltage
Standard voltage:
11 to 14 v
If the voltage is below 11 v, recharge or replace the battery
before proceeding.
Pr ...
Horn system
Parts location
System diagram
Problem symptoms table
Hint:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms are
listed in order of probability in the "suspected area" column of
the table. Check each symptom by c ...
Diagnosis system
Description
The ecm controls the function of cruise control on this
vehicle. Data of the cruise control or dtc can be read
from the dlc3 of the vehicle. When trouble occurs with
cruise control, check that the cruise main indicator
does not come on but dtc inspection is performed.
Theref ...