Firenza L4-121 2.0L VIN K TBI (1987)
Idle Speed/Throttle Actuator - Electronic: Testing and Inspection
Fig. 038 - Wiring Diagram for Chart C-2C Idle Air Control. VIN 1
CHART C2-C
IDLE AIR CONTROL (IAC) SYSTEM CHECK
2.0L (VIN 1) "J" SERIES
FUEL INJECTION (TBI)
Circuit Description:
The ECM controls idle rpm with the IAC valve. To increase idle rpm, the ECM moves the IAC valve out, allowing more air to pass by the throttle
plate. To decrease rpm, it moves the IAC valve in, reducing air flow by the throttle plate. A "Scan" tool will read the ECM commands to the IAC valve
in counts. The higher the counts, the more air allowed (higher idle). The lower the counts, the less air allowed (lower idle).
