Ignition Timing: Specifications

Engine Control Module Scan Tool Data Parameters
Parameter: Spark
18-24 Degrees
The scan tool displays a range of -64 to +64°. The scan tool displays the amount of degrees the PCM commands. The PCM computes the desired spark advance using the following: (1) ECT, (2) engine speed (RPM), (3) load, (4) vehicle speed. The PCM adjusts the timing.

A negative (-) value indicates degrees before top dead center (BTDC) or spark advance; a positive value indicates degrees after top dead center (ATDC) or spark retard.


Engine Control Module Scan Tool Output Controls
Output Control: Spark Control
Enables or disables idle spark command. When commanded ON, the idle spark will be controlled to 13 degrees before top dead center. The normal commanded state is OFF.