Toyota Corolla (E120): Check and replace ecu
Notice
: start an inspection of the connector from the backside of the connector on the wire harness side with the connector connected to the ecu.
When no measurement condition is specified, perform the inspection with the engine stopped and also the ignition switch on.
- First check the ecu ground circuit. If it is faulty, repair it.
If it is normal, the ecu could be faulty. In this case, replace the ecu with one that functions normally and check if the symptoms appear.
- Measure the resistance between the ecu ground
terminal and body ground.
Resistance: 1 Ω or less
- Disconnect the ecu connector, check the ground terminals on the ecu side and wire harness side for bends and check the contact pressure.
Other materials:
Problem symptoms table
If a normal code is displayed during the dtc check but the problem still
occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the
relevant troubleshooting page.
Notice:
when replacing skid control ecu, sensor or etc., Turn the ignition swi ...
Inspection procedure
Hint:
the switch described in this text is a switch for transmitting signals which is
built in the door control transmitter.
1 Check wireless door lock control functions
Normal
2 Replace transmitter battery with normal one
After replacing the transmitter battery with a new or normal o ...
Diagnostic trouble code chart
Hint:
as for the vehicle for mexico, refer to repair manual 2003 corolla (pub. No.
Rm938u).
Parameters listed in the chart may not be exactly the same as your readings due
to the type of instrument
or other factors.
If a malfunction code is displayed during the dtc check in the check mod ...