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:
Terminals of ecu
Oscilloscope wave (*1)
Hint:
terminal: od – gnd
gauge set: 5 v / div, 50 ms / div
condition: during cruise control driving o/d switch on.
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Data list/active test
1. Data list
Hint:
using the data list displayed by the hand–held tester or the obd ii scan tool,
you can read the value of
the switches, sensors, actuators and so on without parts removal. Reading the
data list as a first step
of troubleshooting is one method to shorten diagnostic time.
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Diagnostic trouble code chart
The inspection procedures are shown in the table below. This table allows
efficient and accurate troubleshooting
using the diagnostic trouble codes displayed in the diagnostic trouble code
chart. Proceed with
troubleshooting in accordance with the inspection procedures listed in the
diagnost ...