Description of On-Board Diagnostics

Fig. 52 ECCS Modes:

1. Mode 1 is the normal operating mode that the EGGS system is in whenever the key is on and no other modes have been entered.
2. Mode 2 is used to monitor the air/fuel mixture feedback operation.
3. Mode 3 is the self-diagnostic mode. The trouble codes that are store in memory will be extracted in this mode.
4. Mode 4 is used to check the operation of the on/off switches:
^Idle Switch
^Starter Switch
^Vehicle Speed Sensor
5. Mode 5 is the real time diagnosis system. It will detect failures in the following circuits at the exact moment they are present and output the appropriate code:
^Crank Angle Sensor
^Ignition Signal
^Air Flow Meter
^Fuel Pump