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Nissan Altima L32. Manual - part 507

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-1149

< FUNCTION DIAGNOSIS >

[VQ35DE]

Diagnostic Test Mode I — Bulb Check

In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check MIL circuit. Refer to

EC-1496, "Component Function Check"

Diagnostic Test Mode I — Malfunction Warning

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 uniden-

Diagnostic Test
Mode

KEY and ENG.
Status

Function

Explanation of Function

Mode I

Ignition switch in
ON position

Engine stopped

BULB CHECK

This function checks the MIL bulb for damage (blown, open
circuit, etc.).
If the MIL does not illuminate, check MIL circuit.

Engine running

MALFUNCTION
WARNING

When a malfunction is detected twice in two consecutive
driving cycles (two trip detection logic), the MIL will illumi-
nate to inform the driver that a malfunction has been detect-
ed.
The following malfunctions will illuminate or blink the MIL in
the 1st trip.
• Misfire (Possible three way catalyst damage)
• One trip detection diagnoses

Mode II

Ignition switch in
ON position

Engine stopped

SELF-DIAGNOSTIC
RESULTS

This function allows DTCs and 1st trip DTCs to be read.

MIL

Condition

When the malfunction is detected.

OFF

No malfunction.

EC-1150

< FUNCTION DIAGNOSIS >

[VQ35DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

tified 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.

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

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

onds) - OFF (0.6-seconds) cycle.

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

In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-

function. (See

EC-1555, "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.

• ECM always returns to Diagnostic Test Mode I after the ignition switch is turned OFF.

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

1. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.

2. Repeat the following procedure quickly five times within 5 seconds.

Fully depress the accelerator pedal.

Fully release the accelerator pedal.

3. Wait 7 seconds, fully depress the accelerator pedal and keep it depressed for approx. 10 seconds until the

MIL starts blinking.

4. Fully release the accelerator pedal.

ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).

NOTE:

JMBIA1140GB

Number

Flashes

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-1151

< FUNCTION DIAGNOSIS >

[VQ35DE]

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

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

1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to “How to Set Diagnostic Test Mode II

(Self-diagnostic Results)”.

2. Fully depress the accelerator pedal and keep it depressed for more than 10 seconds.

The emission-related diagnostic information has been erased from the backup memory in the ECM.

3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.

• If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.

• Do not 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 turn off after the vehicle is driven 3 times (driving pattern B) with no malfunction. A 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) with-

out the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and Fuel Injec-

tion 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 CON-

SULT-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

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”.
*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”

PBIB0092E

Items

Fuel Injection System

Misfire

Other

MIL (turns off)

3 (pattern B)

DTC, Freeze Frame Data (no
display)

80 (pattern C)

40 (pattern A)

1st Trip DTC (clear)

1 (pattern C), *

1 (pattern B)

1st Trip Freeze Frame Data
(clear)

*1, *2

1 (pattern B)

EC-1152

< FUNCTION DIAGNOSIS >

[VQ35DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Explanation for Driving Patterns for “Misfire <Exhaust Quality Deterioration>”, “Fuel Injection System”

Driving pattern B means the vehicle operation as per the following:

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

*1: When the same malfunction is de-

tected in two consecutive trips, MIL
will illuminate.

*2: MIL will turn off after vehicle is driven

3 times (pattern B) without any mal-
functions.

*3: When the same malfunction is de-

tected in two consecutive trips, the
DTC and the freeze frame data will be
stored in ECM.

*4: The DTC and the freeze frame data

will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.)

*5: When a malfunction is detected for

the first time, the 1st trip DTC and the
1st trip freeze frame data will be
stored in ECM.

*6: The 1st trip DTC and the 1st trip

freeze frame data will be cleared at
the moment OK is detected.

*7: When the same malfunction is de-

tected in the 2nd trip, the 1st trip
freeze frame data will be cleared.

*8: 1st trip DTC will be cleared when ve-

hicle is driven once (pattern C) with-
out the same malfunction after DTC
is stored in ECM.

JMBIA1417GB

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