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:
How to proceed with troubleshooting
Hint:
carry out troubleshooting in accordance with the procedures on the following
page. Here, only the basic
procedures are shown. Details are provided in the diagnostics section, showing
the most effective methods
for each circuit. Confirm the troubleshooting procedures first for the releva ...
No sound is heard from speaker in all modes
Wiring diagram
Inspection procedure
1 Check lcd (liquid crystal display) for lighting
Lcd illumination check
turn the ignition switch acc.
Turn the radio receiver assembly on.
Standard: lcd illumination of the radio receiver assembly light.
2 Control fader and ...
Circuit description
Monitor description
The ecm commands gearshift by turning the shift solenoid valves ”on/off”.
When there is an open or short
circuit in any shift solenoid valve circuit, the ecm detects the problem and the
mil comes on. Illuminating
the mil, the ecm performs the fail–safe and turns ...