Description of On-Board Diagnostics

The ECU will substitute the input signals for the air flow meter and water temperature sensor if the circuits fail. This will allow the vehicle to driven until repairs can be made.
NOTE: The engine will operate at reduced capacity.

AIR FLOW METER MALFUNCTION
If the ECU senses that the air flow meter output voltage is out of the normal range it will fix the injector duration at a preset value. Engine rpm will be limited to 2000 in order to inform the driver that the ECU is in the "Fail-Safe Mode".

Fig. 90 Water Temperature Sensor Malfunction:

WATER TEMPERATURE SENSOR MALFUNCTION
When the ECU senses that the engine temperature output voltage is out of the normal range, it will substitute voltage at preset values. Refer to the figure for operating conditions.