Malfunction Indicator Lamp: Description and Operation

MALFUNCTION INDICATOR LAMP
1. The malfunction indicator lamp will light up when the ignition switch is turned ON without the engine running. This is a bulb check.
- If the malfunction indicator lamp does not light up.
2. When the engine is started, the malfunction indicator lamp should go off.
If the lamp remains on, the on-board diagnostic system has detected an engine system malfunction.

ON-BOARD DIAGNOSTIC SYSTEM FUNCTION
The on-board diagnostic system has the following four functions.
1. BULB CHECK:
This function checks the MIL bulb for damage (blown, open circuit, etc.).
2. MALFUNCTION WARNING:
This is a usual driving condition. When a malfunction is detected twice (two trip detection logic), the MIL will light up to inform the driver that a malfunction has been detected.
Only the following malfunctions will light up or blink the MIL even in the 1st trip.
- "Misfire (Possible three way catalyst damage)"
- "Three way catalyst function"
- "Closed loop control"
3. SELF-DIAGNOSTIC RESULTS:
This function allows diagnostic trouble codes to be read.
4. FRONT HEATED OXYGEN SENSOR MONITOR:
This function allows the fuel mixture condition (lean or rich), monitored by front heated oxygen sensor, to be read.
Refer to "HOW TO SWITCH DIAGNOSTIC TEST MODES".

DIAGNOSTIC TEST MODE I-BULB CHECK
In this mode, the MALFUNCTION INDICATOR LAMP on the instrument panel should stay ON. If it remains OFF, check the bulb.

DIAGNOSTIC TEST MODE I-MALFUNCTION WARNING




These Diagnostic Trouble Code Numbers are clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS).

DIAGNOSTIC TEST MODE II-SELF-DIAGNOSTIC RESULTS
In this mode, a diagnostic trouble code is indicated by the number of blinks of the MALFUNCTION INDICATOR LAMP as shown.







Long (0.6 second) blinking indicates the number of ten digits, and short (0.3 second) blinking indicates the number of single digits. For example, the malfunction indicator lamp blinks 10 times for 6 seconds (0.6 sec x 10 times) and then it blinks three times for about 1 second (0.3 sec x 3 times). This indicates the DTC "1003" and refers to the malfunction of the park/neutral position switch.
In this way, all the detected malfunctions are classified by their diagnostic trouble code numbers. The DTC "0505" refers to no malfunction. (See DIAGNOSTIC TROUBLE CODE CHART.)




DIAGNOSTIC TEST MODE II-FRONT HEATED OXYGEN SENSOR-MONITOR
In this mode, the MALFUNCTION INDICATOR LAMP displays the condition of the fuel mixture (lean or rich) which is monitored by the front heated oxygen sensor.
To check the front heated oxygen sensor function, start engine in Diagnostic Test Mode II. Then warm it up until engine coolant temperature indicator points to middle of gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Make sure that the MALFUNCTION INDICATOR LAMP comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.