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:
Changing the engine switch positions
1 “LOCK”
The steering wheel is locked and the key can be removed. (Vehicles with an automatic
transmission or continuously variable transmission: The key can be removed only
when the shift lever is in P.) 2 “ACC”
Some electrical components such as the audio system can be used.
3 “ON ...
Overhaul
1. Remove w/head taper screw plug no.2
Using a socket hexagon wench 10, remove the taper
screw plug and gasket.
2. Remove valve lifter
Remove the valve lifters from the cylinder head.
3. Remove valve
Place the cylinder head on wooden blocks.
using sst, compres ...
Definition of terms
Term
Definition
Monitor description
Description of what the ecm monitors and how it detects malfunctions
(monitoring purpose and its details).
Related dtcs
Diagnostic code
Typical enabling condition
Preconditions that allow the ecm to detect ...


