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:
Seat belt pretensioners (front seats)
The pretensioners help the seat belts to quickly restrain the occupants by retracting
the seat belts when the vehicle is subjected to certain types of severe frontal
or side collision.
The pretensioners do not activate in the event of a minor frontal impact, a minor
side impact, a rear impact ...
Check short circuit
If the wire harness is ground shorted as shown in fig. 5,
Locate the section by conducting a resistance check with
the body ground in step (b).
Check the resistance with the body ground.
Disconnect connectors a and c and measure the
resistance between terminals 1 and 2 ...
Circuit description
Shifting from 1st to o/d is performed in combination with on and off of the
shift solenoid valve s1 and s2
controlled by ecm. If an open or short circuit occurs in either of the solenoid
valves, the ecm controls the
remaining normal solenoid valve to allow the vehicle to be operated smoothly
...


