OPERATION > ESA SYSTEMS
The Electronic Control Unit (ECU) is pre-programmed with data for optimum ignition timing under any engine operating condition. Using data from engine sensors (RPM, engine temperature, etc.), The ECU triggers ignition system to provide a spark at precisely the right instant. The ignition system operates on the same principles as a non-ESA system except all timing advance is controlled by the computer rather than by vacuum and mechanical advance mechanisms.
The ECU uses a tachometer signal from the ignition system to detect engine speed and trigger the fuel injectors. Some ignition system problems can be detected by the ECU and will result in a trouble code No. 12, 13 or 14 being set in the computer memory.
OPERATION > NON-ESA SYSTEMS
On Corolla and Corolla FX models, as distributor shaft turns reluctor, reluctor teeth (one for each cylinder) pass magnetic pick-up coil assembly. As air gap changes with approach and pass of each reluctor tooth, magnetic field varies creating a signal in pick-up coil assembly.
The ignitor module senses this signal and turns ignition coil primary circuit on and off. This causes magnetic field in coil primary winding to collapse, resulting in a voltage surge in secondary winding, which fires spark plugs.
TROUBLE SHOOTING > ENGINE CRANKS BUT WILL NOT START
Check for faulty spark plug(s), ignition coil, ignitor, distributor and ignition system wiring. Repair or replace parts as necessary. Check ignition timing and adjust if necessary.
Sunday, March 29th, 2015 AT 7:55 PM