Ignition Timing
WARNING: This page is about a different car, the 1985 Nissan 200SX. However, it is still accessible from the selected car via links, so may be relevant.
The ECCS control unit uses sensor input to determine correct timing. It sends a signal to a power transistor located on coil, which permits current to flow through coil. Timing is advanced and retarded by control unit based on sensor input, built-in programming and detonation sensor signals.