The causes of many of the problems occurring in electric circuitry
are generally the connectors, components, the ECU, the wiring harnesses between connectors,
in that order. These inspection procedures follow this order. They first try to discover a problem
with a connector or a defective component.
CURRENT TROUBLE
Indicates that the status is "Active" and the trouble is currently present. Carry out
troubleshooting as described in the applicable inspection procedure.
PAST TROUBLE
Indicates that the status is "Stored" and the trouble is historic. Since the trouble may
still be present, set the vehicle to the diagnosis code detection condition and check that the
status changes to "Active". If the status does not change from "Stored", observe the applicable
inspection procedure with particular emphasis on connector(s) and wiring harness.
HARNESS CHECK
Check for an open or short circuit in the harness between the terminals which are faulty
according to the connector measurements. Carry out this inspection while referring to the Electrical
Wiring Manual. Here, "Check the wiring harness between the power supply and terminal xx" also
includes checking for blown fuse. For inspection service points when there is a blown fuse,
refer to "Inspection Service Points for a Blown Fuse ."
MEASURES TO TAKE AFTER REPLACING THE ECU
If the trouble symptoms have not disappeared even after replacing the ECU, repeat the
inspection procedure from the beginning.