Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Diagnosis system / Check dlc3
Toyota Corolla (E120): Check dlc3
The vehicle’s ecm uses the iso 9141–2 for communication protocol. The terminal arrangement of the dlc3 complies with sae j1962 and matches the iso 9141–2 format.


Hint
: if the display shows unable to connect to vehicle when you have connected the cable of the obd ii scan tool or the hand–held tester to the dlc3, turned the ignition switch on and operated the scan tool, there is a problem on the vehicle side or tool side.
- If the communication is normal when the tool is connected to another vehicle, inspect the dlc3 on the original vehicle.
- If the communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the service department listed in the tool’s instruction manual.
Inspect battery voltage
Battery voltage: 11 to 14 v
If voltage is below 11 v, recharge the battery before proceeding.
Check mil
- The mil comes on when the ignition switch is turned on
and the engine is not running.
Hint
: if the mil is not illuminated, troubleshoot the mil circuit .
- when the engine is started, the mil should go off. If the mil remains on, it means that the diagnosis system has detected a malfunction or abnormality in the system.
Other materials:
Sound quality is bad only when cd is played(volume is
too low)
Inspection procedure
1 Replace cd with another and recheck
Replace the cd with another and recheck.
Check the installation condition of the radio receiver assembly.
Standard: malfunction disappear.
Check and replace radio receiver assy ...
Problem symptoms table
When the malfunction code is not confirmed in the diagnostic trouble code
check and the problem still can
not be confirmed in the basic inspection, proceed to this problem symptoms
tables and troubleshoot according
to the numbered order given below.
*: A/t only ...


