Code 12 - No Reference Pulses

NOTE: To check ignition system components, see IGNITION SYSTEM in SYSTEM & COMPONENT TESTING - CARBURETED article.

NOTE: Test numbers refer to test numbers on diagnostic chart.

This step checks for poor connection at ignition coil connectors as cause of no reference pulse.
This step determines if reference pulse is being sent to ECM.

Fig 1: Chart 12 - Schematic

Courtesy of ISUZU MOTOR CO.

Fig 2: Chart 12 - Diagnostic Flow Chart

Courtesy of ISUZU MOTOR CO.