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:
Shifting the shift lever
Vehicles without a smart key system:
While the engine switch is in the “ON” position, depress the brake pedal and
move the shift lever.
Vehicles with a smart key system: While the engine switch is in IGNITION ON mode,
depress the brake pedal and move the shift lever.
When shifting the ...
Temporarily engaged gear steps selection mode in the D position
To drive in temporary gear steps selection mode, operate the “-” and “+” paddle
shift switches. The gear steps can then be selected by operating the “-” and “+”
paddle shift switches. By selecting gear step using paddle shift switches, you can
control engine braking forces.
1 ...
Precaution
Caution:
the corolla is equipped with srs, which comprises a driver airbag,
front passenger airbag
and side airbag. Failure to carry out service operations in the correct
sequence could cause
the srs to unexpectedly deploy during servicing, possibly leading to a
serious accident. Fu ...


