Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Ignition coil primary/secondary
circuit / Circuit description
Toyota Corolla (E120): Circuit description
Hint
:
- these dtcs indicate a malfunction related to the primary circuit.
- If dtc p0351 is displayed, check the no.1 Ignition coil with igniter circuit.
- If dtc p0352 is displayed, check the no.2 Ignition coil with igniter circuit.
- If dtc p0353 is displayed, check the no.3 Ignition coil with igniter circuit.
- If dtc p0354 is displayed, check the no.4 Ignition coil with igniter circuit.
A direct ignition system (dis) is used on this vehicle. The dis improves the ignition timing accuracy, reduces high–voltage loss, and enhances the overall reliability of the ignition system by eliminating the distributor.
The dis is a 1–cylinder ignition system which ignites one cylinder with one ignition coil. In the 1–cylinder ignition system, the one spark plug is connected to the end of the secondary winding. High voltage generated in the secondary winding is applied directly to the spark plug. The spark of the spark plug passes from the center electrode to the ground electrode.
The ecm determines the ignition timing and outputs the ignition signals (igt) for each cylinder. Using the ignition (igt) signal, the ecm turns on and off the power transistor inside the igniter and this switches on and off the current to the primary coil. When the current flow to the primary coil is cut off, high–voltage is generated in the secondary coil and this voltage is applied to the spark plugs to spark inside the cylinders.
As the ecm cuts the current to the primary coil, the igniter sends back the ignition confirmation (igf) signal for each cylinder ignition to the ecm.
Monitor description
If the ecm does not receive the ignition confirmation signal (igf) after sending the ignition signal (igt), it interprets this as a fault in the igniter and sets a dtc.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Component operating range
Wiring diagram
Other materials:
Replacement
1. Drain brake fluid
Notice:
wash the brake fluid off immediately if it comes into contact with any painted
surface.
2. Remove air cleaner cap sub–assy
3. Remove air cleaner case sub–assy
remove the air cleaner element, then remove the 3 bolts and air
cleaner case sub–assy.
...
Calibrating the compass
The direction display deviates from
the true direction determined by the earth’s magnetic field. The amount of deviation
varies according to the geographic position of the vehicle.
If you cross over a map boundary shown in illustration, the compass will deviate.
To obtain higher precision or ...
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 ...