Electronic Feedback Carburetor System Diagnosis

NOTES:
a. Before performing system diagnosis, ensure engine and all related systems are in proper operating condition.
b. The electronic feedback carburetor system can be checked using a voltmeter and an ``ECI checker''. Ensure battery is fully charged, and all specified conditions are observed as called out in chart.
c. If battery terminals are disconnected while engine is running or when ignition switch is in the ON position, damage to computer or semiconductors may result.



ECI CHECK PROCEDURE
Using ECI checker, tool No. MD998451, and Feedback Carburetor (FBC) harness Connector D, tool No. MD998455, check Electronic Control Unit (ECU) input and output signals, using the following procedures.

1. Turn ignition switch to ``Lock.''
2. Disconnect large and small harness connectors from ECU.
3. Place check switch of ECI Checker to Off, then turn the select switch to A.
4. Connect FBC harness connector D to connectors of ECI checker, then connect harness to ECU.
5. Perform ECI diagnostic checks.

Fig. 27a Electronic feedback carburetor system diagnosis (Part 1 of 2).:

Fig. 27b Electronic feedback carburetor system diagnosis (Part 2 of 2).:

6. If checker indication is not as specified, check suspected sensor or related wiring and repair or replace as necessary. After repair or replacement of malfunctioning system component, recheck system using ECI checker.
7. Set ignition switch to Lock, then disconnect ECI checker and FBC harness connector D.
8. Connect body side harness connectors to the ECU, then road test vehicle.