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:
Circuit description
The vapor pressure sensor and the vsv for the canister closed valve (ccv) are
used to detect abnormalities
in the evaporative emission control system. The ecm decides whether there is an
abnormality in the evaporative
emission control system based on the vapor pressure sensor signal.
Dtc p0 ...
Overhaul
1. Remove manual transmission filler plug
Remove the manual transmission filler plug and gasket
from the manual transmission case.
2. Remove drain (mtm) plug sub–assy
Remove the drain (mtm) plug sub–assy and gasket from
the manual transmission case.
3. Remove speedomete ...
Circuit description
Refer to dtc p0130
Hint:
the ecm provides a pulse width modulated control circuit to adjust current
through the heater. The heated
oxygen sensor heater circuit uses a relay on the b+ side of the circuit.
Monitor description
The ecm uses the heated oxygen sensor information to regulate t ...


