Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Ignition coil primary/secondary
circuit / Inspection procedure
Toyota Corolla (E120): Inspection procedure
Hint
: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Perform simulation test
- Clear the dtc
- shuffle arrangement of the ignition coil and igniters.
Notice
: do not shuffle the connectors.
- perform the simulation test.
Result:



2 Inspect ecm(igt1, igt2, igt3, igt4 and igf signal)

- Inspection using the oscilloscope.
- during cranking or idling, check the waveform between terminals igt1 to igt4 and e1, igf and e1 of the ecm connector.
Standard:

Hint
: correct waveform is as shown in the diagram on the left.



3 Check harness and connector(ignition coil assy – ecm)

- Disconnect the i2, i3, i4 or i5 ignition coil and igniter connector.
- disconnect the e3 ecm connector.
- check the resistance between the wire harness side connectors.
Standard (check for open):

Standard (check for open):

Standard (check for short):

Standard (check for short):


- Reconnect the ecm connector.
- reconnect the ignition coil and igniter connector


4 Inspect ignition coil assy(power source)

- Disconnect the i2, i3, i4 or i5 ignition coil and igniter connector.
- check the resistance between the wire harness side connectors.
Standard (check for open):

- Turn the ignition switch on position.
- measure the voltage between the terminal of the wire harness side connector and body ground.
Standard:

- Reconnect the ignition coil and igniter connector.


5 Check harness and connector(ignition coil assy – ignition switch)

- Disconnect the i2, i3, i4 or i5 ignition coil and igniter connector.
- disconnect the i10 ignition switch connector.
- check the resistance between the wire harness side connectors.
Standard (check for open):

Standard (check for short):


- Reconnect the ignition coil and igniter connector.
- reconnect the ignition switch connector.


Replace ignition coil assy
Other materials:
Circuit description
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim includes
the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain
the air–fuel ratio at stoichiomet ...
Inspection procedure
1 Check d squib circuit(airbag sensor assy center – horn button
assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connector between the airbag sensor
assy center and the horn button assy.
for the black ...
Circuit description
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...


