Without Scan Tool

SELF DIAGNOSIS SYSTEM
The On-Board Diagnostic system is so designed that the circuits handling the input signals from the sensors and output signals for driving actuator are continuously monitored by the Engine Control Module (ECM). In the event of a failure, the ECM stores it in memory and operates the malfunction indicator lamp (MIL) on the instrument panel when the nature of trouble is important, to warn the operator of failure.

NOTE: The On-Board Diagnostic system is capable of troubleshooting the electric circuits in the Closed Loop Emission Control system only and does not cover the trouble in the sensors, actuators or the engine itself.






Warning to Operator
When a failure has developed in the following systems while driving, the malfunction indicator lamp within the instrument panel is operated to warn the driver of system failure.
- Mass air flow sensor system
- Engine coolant temperature sensor system
- Vehicle speed sensor system
- Heated oxygen sensor system
- Fuel injector system
- ECM







DIAGNOSTIC TROUBLE CODE (DTC) NO. DISPLAY
1. When the DTC test lead in the vicinity of the ECM is connected with the ignition switch turned to ON position, the diagnostic trouble code stored in memory is displayed in the malfunction indicator lamp.

2. With the engine not in operation, first, the DTC 12 is indicated three times, which means that the ECM is functioning normally. Then other DTCs indicating other malfunctions, if any, come on three times each in the ascending order of DTC numbers.

3. The malfunction DTCs are also read out when the engine is running. In this case, the DTC 12 is not indicated.

TROUBLE CODE INDICATION
- The Diagnostic Trouble Code (DTC) is indicated by intermittent operation of the lights which represent the malfunction code figures.






For instance, (see image), the light operates to indicate malfunction code "24".






- The blinking consists of the patterns and individual patterns will repeat to indicate abnormality. When more than one abnormality takes place, related patterns will repeat 3 times each. Having completed all the pertinent patterns, it returns to the initial pattern. Then the same is repeated.






- Flashing Sequences (Engine not in operation)
DTC 12 is indicated first. And then, the malfunction DTC with the smallest number is indicated. One DTC is indicated three times at the interval of 3.2 seconds. When all the DTCs have been indicated, DTC 12 is indicated again, then the first DTC, the second DTC and so on.