Secondary Air System Check - Impulse

To check secondary air system, proceed to TESTING SECONDARY AIR SYSTEM (CHART C-2C, IMPULSE). See Fig 1 .

NOTE: Test number refer to test numbers in flow chart.

Without proper vacuum being available at solenoid, system will not function properly.
When ignition is on and engine is not running, solenoid should not be energized. Since solenoid is normally closed, vacuum should not be able to pass to actuator.
With diagnostic terminal grounded, ECM should ground circuit No. 476 which should energize solenoid and allow vacuum to pass to actuator.
This step checks ability of vacuum actuator to be able to move secondary intake valve linkage.
This step, as well as the following steps in flow chart, checks for circuit continuity.

Fig 1: Chart C-2C Flow Chart: Secondary Air System (Impulse)

Courtesy of ISUZU MOTOR CO.