Description of On-Board Diagnostics

ON-BOARD DIAGNOSTIC SYSTEM

Malfunction Indicator Lamp (MIL) Operation

Malfunction Indicator Light:

1. The MIL will come on when the ignition is switched ON and the engine is not running.
2. When the engine is started, the MIL should go off.
- If the light remains on, the diagnosis system has detected a malfunction or abnormality in the system.


DIAGNOSTIC MODES

Normal Mode



- If no malfunction has been detected, the MIL will alternately blink ON and OFF at 0.26 second intervals.



- In the event of a malfunction, the light will blink every 0.52 seconds.
- The 1st number of blinks will equal the 1st digit of a two digit diagnostic trouble code, and after a 1.5 second pause, the 2nd number of blinks will equal the second digit.
- If there are two or more codes, there will be a 2.5 second pause between each code.
- After all the codes have been output, there will be a 4.5 second pause and they will all be repeated as long the terminals TE1 and E1 of the DLC1 are connected.


Test mode:
- Compared to the Normal mode, the Test mode has an increased sensing ability to detect malfunctions.
- It can also detect malfunctions in the starter signal circuit, air conditioning signal and PNP switch signal.
- Furthermore, the same diagnostic items which are detected in the Normal mode can also be detected in the Test mode.



- Jump terminals TE2 and E1 to initiate the Test mode.
- Test mode will not start if terminals TE2 and E1 are connected after the ignition switch is turned ON.
- The starter signal and vehicle speed signal will be diagnosed by the ECM as malfunctions, and code numbers42, and 43 will be output, if the operation in step 4 is not done.
- When the automatic transmission shift lever is in the "D", "2", "L" or "R" shift position, or when the air conditioning is on or when the accelerator pedal is depressed, code "51" (Switch condition signal) is output. This is normal operation.


DIAGNOSTIC TROUBLE CODE OUTPUT
- To obtain an output of diagnostic trouble codes (DTC), refer to "How to Display and Read Diagnostic Trouble Codes".
- Reading Diagnostic Trouble Codes

Normal system operation (no malfunction) indication.



- The light will alternately blink ON and OFF at 0.26 second intervals.

Malfunction code indication.



- In the event of a malfunction, the light will blink every 0.52 seconds.
- The first number of blinks will equal the first digit of the 2 digit diagnostic trouble code, and after a 1.5 second pause, the second number of blinks will equal the second digit of the diagnostic trouble code.
- If there are multiple codes, there will be a 2.5 second pause between each code.
- After all the codes have been output, there will be a 4.5 second pause and they will be repeated.
- This will continue as long as TE1 and E1 are connected.

Notes:
- In the event of a number of trouble codes, indication will begin from the smaller value and continue to the larger.
- When 2 or more codes are indicated, the lowest number (code) will appear first.
- All detected diagnostic trouble codes, except code numbers 43, 51 and 53 will be retained in memory by the ECM from the time of detection until cancelled out.
- Once the malfunction is repaired, the MIL in the combination meter will go off but the diagnostic trouble code (s) remains stored in ECM memory (except for code numbers 43, 51 and 53).

2 trip detection logic:



- Diagnostic trouble codes 25, 26 and 71 use "2 trip detection logic". With this logic, when a malfunction is first detected, the malfunction is temporarily stored in the ECM memory. If the same case is detected again during the second drive test, this second detection causes the MIL to light up.
- The 2nd trip repeats the same mode a second time. However, the ignition switch must be turned OFF between the 1st time and 2nd time.
HINT: In the Test Mode, 2 trip detection logic is disabled and the MIL lights up the 1st time a malfunction is detected.

Trouble Code Detection Driving Patterns
- Diagnostic trouble codes 21, 25, 26, 27 and 71 are only set if a specific driving pattern is followed.
- For those codes, a description of the required driving pattern is included with the appropriate diagnostic chart under "Trouble Code Charts".