Malfunction Indicator Lamp
DESCRIPTION
1. The MIL will light up when the ignition switch is turned ON without the engine running. This is a bulb check.
- If the MIL does not light up, check bulb and bulb circuit.
2. When the engine is started, the MIL should go off.
- If the MIL 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.
MIL Flashing without DTC
If the ECM is in Diagnostic Test Mode II, MIL may flash when engine is running. In this case, check ECM test mode selector following "How to Switch Diagnostic Test Mode". The following emission-related diagnostic information is cleared when the ECM memory is erased.
1. Diagnostic trouble codes
2. 1st trip diagnostic trouble codes
3. Freeze frame data
4. 1st trip freeze frame data
5. System readiness test (SRT) codes
6. Test values
7. Others
How to Switch Diagnostic Test Modes
Diagnostic Test Mode I - Bulb Check
In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check the bulb.
Diagnostic Test Mode I - Malfunction Warning
These DTC Numbers are clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS).
Diagnostic Test Mode II - Self-diagnostic Results
- In this mode, the DTC and 1st trip DTC are indicated by the number of blinks of the MIL.
- The DTC and 1st trip DTC are displayed at the same time. If the MIL does not illuminate in diagnostic test mode I (Malfunction warning), all displayed items are 1st trip DTC's. If only one code is displayed when the MIL illuminates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are displayed, they may be either DTC's or 1st trip DTC's. DTC No. is same as that of 1st trip DTC. These unidentified codes can be identified by using the CONSULT or GST. A DTC will be used as an example for how to read a code.
- Long (0.6 second) blinking indicates the two LH digits of number and short (0.3 second) blinking indicates the two RH digits of number. For example, the MIL 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 DTC numbers. The DTC "0505" refers to no malfunction. (See Powertrain Management/Computers and Control Systems/Testing and Inspection/Procedures/Trouble Code Diagnostic Procedures. Testing and Inspection
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the backup memory in the ECM when the diagnostic test mode is changed from Diagnostic Test Mode II to Diagnostic Test Mode 1. (Refer to "How to Switch Diagnostic Test Modes".)
- If the battery is disconnected, the DTC will be lost from the backup memory after approx. 24 hours.
- Be careful not to erase the stored memory before starting trouble diagnoses.
Diagnostic Test Mode II - Front Heated Oxygen Sensor Monitor
In this mode, the MIL 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 the Diagnostic Test Mode II and warm it up until engine coolant temperature indicator points to the middle of the gauge.
- Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the MIL comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.