Timing Advance System

Ignition timing advance is controlled by the ECU based upon sensor input signals reflecting ignition timing needs. If timing problems are experienced, inspect input signals for proper operation. See appropriate component or ECU PIN VOLTAGE CHARTS in PIN VOLTAGE CHART S article. Inputs which help control timing include the following:

• Crank angle sensor
• Airflow meter
• Engine (coolant) temperature
• Idle switch in idle position
• Ignition switch crank signal
• Battery voltage.