October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.
Electronic Ignition Timing Advance
- Electronic Spark Timing (EST) is controlled by ECM. Ignition module sends a reference signal on Yellow/Red wire to ECM when engine is cranking. With engine speed less than 400 RPM, ignition module controls ignition timing.
- With engine speed greater than 400 RPM, ECM applies 5 volts on by-pass line (Yellow/Green wire) to switch timing control to EST mode. In EST mode, ECM controls the ignition timing. If problem exists with EST, a Code 42 will be set. See TESTS W/CODES
article in the ENGINE PERFORMANCE Section.