Malfunction Indicator Lamp (Mil): Description

The MIL is located on the combination meter.

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, refer to "COMPONENT FUNCTION CHECK ".
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.

Fig 1: Identifying Malfunction Indicator Lamp (MIL)
Courtesy of NISSAN MOTOR CO., U.S.A.

On Board Diagnostic System Function

The on board diagnostic system has the following three functions.

DIAGNOSTIC TEST MODE FUNCTION CHART

Diagnostic Test Mode	KEY and ENG. Status	Function	Explanation of Function
Mode I	Courtesy of NISSAN MOTOR CO., U.S.A.	BULB CHECK	This function checks the MIL bulb for damage (blown, open circuit, etc.). If the MIL does not come on, check MIL circuit.
Mode I	Courtesy of NISSAN MOTOR CO., U.S.A.	MALFUNCTION WARNING	This is a usual driving condition. When a malfunction is detected twice in two consecutive driving cycles (two trip detection logic), the MIL will light up to inform the driver that a malfunction has been detected. The following malfunctions will light up or blink the MIL in the 1st trip. Misfire (Possible three way catalyst damage) One trip detection diagnoses
Mode II	Courtesy of NISSAN MOTOR CO., U.S.A.	SELF-DIAGNOSTIC RESULTS	This function allows DTCs and 1st trip DTCs to be read.

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. Refer to "COMPONENT FUNCTION CHECK ".

Diagnostic Test Mode I - Malfunction Warning

MIL CONDITION CHART

MIL	Condition
ON	When the malfunction is detected.
OFF	No malfunction.

This DTC number is 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 as shown below. 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 DTCs. 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 DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These unidentified codes can be identified by using the CONSULT-III or GST. A DTC will be used as an example for how to read a code.

Fig 2: DTC Blinking Pattern

Courtesy of NISSAN MOTOR CO., U.S.A.

A particular trouble code can be identified by the number of four-digit numeral flashes as follows.

NUMBER AND FLASHES DESCRIPTION

Number	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F
Flashes	10	1	2	3	4	5	6	7	8	9	11	12	13	14	15	16

The length of time the 1, 000th-digit numeral flashes on and off is 1.2 seconds consisting of an ON (0.6-second) - OFF (0.6-second) cycle.

The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.

A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later numeral appears on the display 1.3 seconds after the former numeral has disappeared.

A change from one trouble code to another occurs at an interval of 1.8-second OFF.

In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no malfunction. (See "DTC INDEX ")

How to Switch Diagnostic Test Mode

NOTE:

It is better to count the time accurately with a clock.
It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has a malfunction.
Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.

HOW TO SET DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)

Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
Repeat the following procedure quickly five times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts blinking.
NOTE: Do not release the accelerator pedal for 10 seconds if MIL may start blinking on the halfway of this 10 seconds. This blinking is displaying SRT status and is continued for another 10 seconds.
Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).

NOTE: Wait until the same DTC (or 1st trip DTC) appears to confirm all DTCs certainly.

Fig 3: Identifying ON/OFF Position Of Ignition Switch And Depressed/Released Position Of Accelerator Pedal
Courtesy of NISSAN MOTOR CO., U.S.A.

HOW TO ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)

Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to " HOW TO SET DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)".
Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup memory in the ECM.
Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.

How to Erase Diagnostic Test Mode II (Self-diagnostic Results)

The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to " HOW TO ERASE DIAGNOSTIC TEST MODE II (SELF-DIAGNOSTIC RESULTS)".

If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
Be careful not to erase the stored memory before starting trouble diagnoses.

OBD System Operation Chart

Relationship Between MIL, 1st Trip DTC, DTC and Detectable Items

When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are stored in the ECM memory.
When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are stored in the ECM memory, and the MIL will come on.
The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction occurs while counting, the counter will reset.
The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A) without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times (driving pattern C) without the same malfunction recurring. The "TIME" in "SELF-DIAGNOSTIC RESULTS" mode of CONSULT-III will count the number of times the vehicle is driven.
The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.

Summary Chart

SUMMARY CHART

Items

Fuel Injection System

Misfire

Other

MIL (goes off)

3 (pattern B)

DTC, Freeze Frame Data (no display)

80 (pattern C)

40 (pattern A)

1st Trip DTC (clear)

1 (pattern C), ⁽¹⁾

1 (pattern B)

1st Trip Freeze Frame Data (clear)

⁽¹⁾, ⁽²⁾

1 (pattern B)

For details about patterns B and C under "Fuel Injection System" and "Misfire", see EXPLANATION FOR DRIVING PATTERNS FOR "MISFIRE & EXHAUST QUALITY DETERIORATION""FUEL INJECTION SYSTEM".
For details about patterns A and B under Other, see EXPLANATION FOR DRIVING PATTERNS FOR "MISFIRE & EXHAUST QUALITY DETERIORATION""FUEL INJECTION SYSTEM" "FUEL INJECTION SYSTEM".

⁽¹⁾	Clear timing is at the moment OK is detected.

⁽²⁾	Clear timing is when the same malfunction is detected in the 2nd trip.

Relationship Between MIL, DTC, 1st Trip DTC and Driving Patterns for "Misfire < Exhaust Quality Deterioration >",

"Fuel Injection System"

Fig 4: Vehicle Speed Driving Pattern

Courtesy of NISSAN MOTOR CO., U.S.A.

Explanation for Driving Patterns for "Misfire < Exhaust Quality Deterioration >""Fuel Injection System"

< Driving Pattern B >

Driving pattern B means the vehicle operation as follows:

All components and systems should be monitored at least once by the OBD system.

The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
The B counter will be counted up when driving pattern B is satisfied without any malfunction.
The MIL will go off when the B counter reaches 3. (*2 in "OBD SYSTEM OPERATION CHART")

< Driving Pattern C >

Driving pattern C means the vehicle operation as follows:

The following conditions should be satisfied at the same time:

Engine speed: (Engine speed in the freeze frame data) ±375 rpm

Calculated load value: (Calculated load value in the freeze frame data) x (1±0.1) [%]

Engine coolant temperature (T) condition:

When the freeze frame data shows lower than 70°C (158°F), T should be lower than 70°C (158°F).
When the freeze frame data shows higher than or equal to 70°C (158°F), T should be higher than or equal to 70°C (158°F).

Example:

If the stored freeze frame data is as follows:

Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80°C (176°F)

To be satisfied with driving pattern C, the vehicle should run under the following conditions:

Engine speed: 475 - 1, 225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70°C (158°F)

The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.
The C counter will be counted up when vehicle conditions above is satisfied without the same malfunction.
The DTC will not be displayed after C counter reaches 80.
The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC is stored in ECM.

Relationship Between MIL, DTC, 1st Trip DTC and Driving Patterns Except For "Misfire < Exhaust Quality Deterioration >""Fuel Injection System"

Fig 5: Vehicle Speed Driving Pattern

Courtesy of NISSAN MOTOR CO., U.S.A.

Explanation for Driving Patterns Except for "Misfire < Exhaust Quality Deterioration >""Fuel Injection System"

< Driving Pattern A >

Fig 6: Engine Coolant Temperature And Engine Speed Graph

Courtesy of NISSAN MOTOR CO., U.S.A.

The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
The DTC will not be displayed after the A counter reaches 40.

< Driving Pattern B >

Driving pattern B means the vehicle operation as follows:

All components and systems should be monitored at least once by the OBD system.

The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
The B counter will be counted up when driving pattern B is satisfied without any malfunctions.
The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).