Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Supplemental restraint system / Source voltage drop
Toyota Corolla (E120): Source voltage drop
Other materials:
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, ...
Inspection procedure
1 Check un–lock warning switch assy
Disconnect the key unlock warning switch connector.
check the continuity between the terminals of the key unlock
warning switch connector, as shown in the illustration
and table.
Standard:
2 Check wire harness (tvip ecu unlock warni ...
Circuit description
When the ignition switch is turned on, battery positive voltage is applied to
the coilwhich closes the contacts
of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.
This signal causes current to flow to the coil, closing the contacts of the efi
relay and supplyin ...