Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / General information
Toyota Corolla (E120): General information
There are many ecu controlled systems used in the corolla. In general, ecu controlled system are considered to be very intricate and require a high level of technical knowledge and expert skill to troubleshoot.
The fact is, however, that if you proceed by inspecting the circuits one by one, troubleshooting of these systems is not complex. If you have adequate understanding of the system and basic knowledge of electricity, the problem can be accurately diagnosed and fixed. This manual is designed based on the above principle to help service technicians perform accurate and effective troubleshooting, and is compiled for the following major ecu controlled systems: the troubleshooting procedures are described on the following pages.
System
- Sfi system
- Abs with ebd system
- Electronic controlled automatic transaxle [ect]
- Supplemental restraint system
- Audio system
- Combination meter
- Power door lock control system
- Wireless door lock control system
- Toyota vehicle intrusion protection system
- Cruise control system
For using hand–held tester
- Before using the tester, the tester’s operator manual should be read thoroughly.
- If the tester cannot communicate with the ecu controlled systems when you have connected the cable of tester to the dlc3, turned the ignition switch on and operated the tester, there is a problem on the vehicle side or tester side.
- If the communication is normal when the tester is connected to another vehicle, inspect the diagnosis data link line (bus line) or ecu power circuit of the vehicle.
- If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself, so perform the self test procedures outlined in the tester operator’s manual.
Other materials:
Circuit description
The srs warning light is located on the combination meter.
When the srs is normal, the srs warning light lights up for approx. 6 Seconds
after the ignition switch is
turned from the lock position to on position, and then turns off automatically.
If there is a malfunction is the srs, the srs ...
Driving assist systems
To keep driving safety and
performance, the following
systems operate automatically
in response to various
driving situations. Be
aware, however, that these
systems are supplementary
and should not be relied
upon too heavily when operating
the vehicle.
Summary of the driving
assist systems
■ ABS ( ...
Inspection procedure
Hint:
hand–held tester only:
narrowing down the trouble area is possible by performing ”a/f control” active
test (heated oxygen
sensor or other trouble areas can be distinguished).
Perform active test using hand–held tester (a/f control).
Hint:
”a/f control” is the active te ...