Federal Models

Component Locations:

The CIS - E Computerized Engine Control system consists of the basic CIS (Continuous Injection System) fuel injection system and electronic controls which are added for air/fuel mixture correction. The electronic control unit (ECU) receives input signals from the airflow sensor position indicator (potentiometer), coolant temperature sensor, transistorized ignition system (EZL), throttle valve switch, altitude sensor, vehicle speed sensor, A/C compressor, transmission range indicator, and oxygen sensor. The ECU processes these input signals and calculates the appropriate correction value which is sent to the electro-hydraulic actuator, air injection relay, the purge valve relay, and the idle control valve.
Federal models are equipped with "On Board Diagnostic" trouble shooting capabilities. If a fault occurs in the oxygen sensor circuit the "CHECK ENGINE" light will illuminate alerting the driver of an emission related malfunction and the control unit will record the fault. Hard failures and intermittent failures will cause the light to remain on until the malfunction is repaired. If a CIS - E system sensor fails, the control unit will use a substitute value in its calculations to continue engine operation (limp home mode). An On Board Diagnostic Connector and impulse counter is used to extract trouble codes. Federal and California control units are not interchangeable.

EZL Electronic Ignition System Layout:

Dwell and ignition angle are determined by the EZL transistorized ignition system. The EZL electronic control unit (ECU) receives input signals from the ignition switch, crankshaft position sensor, intake manifold vacuum signal, coolant temperature sensor, throttle valve switch, and the CIS-E control unit. Like the CIS - E control unit, the EZL control unit processes these signals, calculates the appropriate dwell/ignition angle, and simultaneously switches the ignition coil ground circuit.