Mirage L4-1597cc 1.6L DOHC Turbo (1989)
Idle Air Control Motor (Stepper Motor): Testing and Inspection
***UPDATED BY TSB #89-16-003, June, 1989
System Schematic
To test the Idle Speed Control (ISC) Servo (also called a Stepper Motor), located on the throttle body, proceed as follows.
OSCILLOSCOPE TEST
Oscilloscope Test
1. Connect the probe of the scope to the pick-up points shown in the System Schematic.
2. Start the engine.
3. When the air conditioner is turned on, the idle speed will increase as the ISC control is activated. Check the pattern on the scope and verify the
operation of the ISC motor. The scope pattern can only be observed when the ISC is operating. If scope pattern is not as depicted in image, continue
with the rest of the test procedures before replacing the assembly.
INITIAL TEST
