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:
Communication system
Horn system
Location
Problem symptoms table
Inspection
1. Inspect low pitched horn assy
Connect the positive (+) lead from the battery to the terminal
and the negative (–) lead to the horn body, and check
that the horn blows.
If the result is not as specified, replace the ...
Circuit description
Hint:
these dtcs indicate a malfunction related to the primary circuit.
If dtc p0351 is displayed, check the no.1 Ignition coil with igniter
circuit.
If dtc p0352 is displayed, check the no.2 Ignition coil with igniter
circuit.
If dtc p0353 is displayed, check the no.3 Ignition coil ...
Inspection procedure
1 Check fuse(ecu–ig)
Remove the ecu–ig fuse from the instrument panel j/b.
check the continuity of the ecu–ig fuse.
Ok: continuity
2 Inspect terminal voltage(b)
Remove the cruise control ecu assy with connector still
connected.
turn the ignition switch ...


