Nissan Sentra. Manual - part 342

EC-64

< SYSTEM DESCRIPTION >

[MRA8DE]

DIAGNOSIS SYSTEM (ECM)

• ECM blinks MIL for about 10 seconds if all SRT codes are not set.

MALFUNCTION WARNING MODE

Description

In this function ECM turns on or blinks MIL when it detects a malfunction in the emission control system com-

ponents and/or the powertrain control components (which affect vehicle emissions) to inform the driver that a

malfunction has been detected.

Operation Procedure

1. Turn ignition switch ON.
2. Check that MIL illuminates.

If it remains OFF, check MIL circuit. Refer to 

EC-61, "DIAGNOSIS DESCRIPTION : System Readiness

Test (SRT) Code"

.

3. Start engine and let it idle.

• For two trip detection logic diagnoses, ECM turns on MIL when it detects the same malfunction twice in

the two consecutive driving cycles.

• For 1st trip detection logic diagnoses, ECM turns on MIL when it detects a malfunction in one driving

cycle.

• ECM blinks MIL when it detects a malfunction that may damage the three way catalyst (misfire).

SELF-DIAGNOSTIC RESULTS MODE

Description

This function allows to indicate DTCs or 1st trip DTCs stored in ECM according to the number of times MIL is

blinking.

How to Set Self-diagnostic Results 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 mal-

function.

• After ignition switch is turned off, ECM is always released from the “self-diagnostic results” mode.
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.

NOTE:

Do not release the accelerator pedal for 10 seconds if MIL starts blinking during this period. This blinking

is displaying SRT status and is continued for another 10 seconds.

4. Fully release the accelerator pedal.

JMBIA1515GB

DIAGNOSIS SYSTEM (ECM)

EC-65

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ECM has entered to “Self-diagnostic results” mode.

NOTE:

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

How to Read Self-diagnostic Results

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 “malfunction warning” mode, 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 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 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.

PBIB0092E

PBIB3005E

Number

0

1

2

3

4

5

6

7

8

9

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Flashes

10

1

2

3

4

5

6

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11

12

13

14

15

16

EC-66

< SYSTEM DESCRIPTION >

[MRA8DE]

DIAGNOSIS SYSTEM (ECM)

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

function. Refer to 

EC-94, "DTC Index"

.

How to Erase Self-diagnostic Results

By performing this procedure, ECM memory is erased and the following diagnostic information is erased as

well.

• Diagnostic trouble codes

• 1st trip diagnostic trouble codes

• Freeze frame data

• 1st trip freeze frame data

• System readiness test (SRT) codes

• Test values

NOTE:

Also, if a battery terminal is disconnected, ECM memory is erased and the diagnostic information as listed

above is erased. (The amount of time required for erasing may vary from a few seconds to several hours.)
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Set ECM in “self-diagnostic results” mode.
6. The diagnostic information has been erased from the backup memory in the ECM.

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

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

CONSULT Function

INFOID:0000000009758389

FUNCTION

*: The following emission-related diagnostic information is cleared when the ECM memory is erased.
• Diagnostic trouble codes
• 1st trip diagnostic trouble codes
• Freeze frame data
• 1st trip freeze frame data
• System readiness test (SRT) codes
• Test  values

SELF DIAGNOSTIC RESULTS MODE

Self Diagnostic Item

Regarding items of DTC and 1st trip DTC, refer to 

EC-94, "DTC Index"

.

How to Read DTC and 1st Trip DTC

DTCs and 1st trip DTCs related to the malfunction are displayed in “Self-diag results”.

• When ECM detects a 1st trip DTC, “1t” is displayed for “TIME”.

• When ECM has detected a current DTC, “0” is displayed for “TIME”.

• If “TIME” is neither “0” nor “1t”, the DTC occurred in the past and ECM shows the number of times the vehi-

cle has been driven since the last detection of the DTC.

Diagnostic test mode

Function

Self Diagnostic Results

Self-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data 
can be read and erased quickly.*

Data Monitor

Input/Output data in the ECM can be read.

Work Support

This mode enables a technician to adjust some devices faster and more accurately by following the in-
dications on the CONSULT unit.

Active Test

Diagnostic Test Mode in which CONSULT drives some actuators apart from the ECMs and also shifts 
some parameters in a specified range.

Ecu Identification

ECM part number can be read.

DTC Work Support

The use of this mode enables quick and accurate performance of Confirmation Procedure.

DIAGNOSIS SYSTEM (ECM)

EC-67

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How to Erase DTC and 1st Trip DTC

NOTE:

• If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10

seconds and then turn it ON (engine stopped) again.

• If the DTC is not for CVT related items (see 

EC-94, "DTC Index"

), skip step 1.

1. Erase DTC in TCM. Refer to 

TM-105, "Description"

.

2. Select “ENGINE” using CONSULT.

3. Select “SELF-DIAG RESULTS”.

4. Touch “ERASE”. (DTC in ECM will be erased.)

Freeze Frame Data and 1st Trip Freeze Frame Data

*: The items are the same as those of 1st trip freeze frame data.

DATA MONITOR MODE

Monitored Item

NOTE:

• The following table includes information (items) inapplicable to this vehicle. For information (items) applica-

ble to this vehicle, refer to CONSULT display items.

• For reference values of the following items, refer to 

EC-77, "Reference Value"

.

Freeze frame data item*

Description

DIAG TROUBLE CODE
[PXXXX]

The engine control component part/control system has a trouble code the is displayed as PXXXX. (Refer 
to 

EC-94, "DTC Index"

.)

FUEL SYS-B1

• “Fuel injection system status” at the moment a malfunction is detected is displayed.
• One of the following mode is displayed.

Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop

CAL/LD VALUE [%]

The calculated load value at the moment a malfunction is detected is displayed.

COOLANT TEMP [

°C] or 

[

°F]

The engine coolant temperature at the moment a malfunction is detected is displayed.

L-FUEL TRM-B1 [%]

• “Long-term fuel trim” at the moment a malfunction is detected is displayed.
• The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule 

than short-term fuel trim.

S-FUEL TRM-B1 [%]

• “Short-term fuel trim” at the moment a malfunction is detected is displayed.
• The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel 

schedule.

ENGINE SPEED [rpm]

The engine speed at the moment a malfunction is detected is displayed.

VEHICL SPEED
[km/h] or [mph]

The vehicle speed at the moment a malfunction is detected is displayed.

ABSOL TH·P/S [%]

The throttle valve opening angle at the moment a malfunction is detected is displayed.

B/FUEL SCHDL [msec]

The base fuel schedule at the moment a malfunction is detected is displayed.

INT/A TEMP SE [

°C] or 

[

°F]

The intake air temperature at the moment a malfunction is detected is displayed.

FUEL SYS-B2

These items are displayed but are not applicable to this model.

L-FUEL TRM-B2 [%]

S-FUEL TRM-B2 [%]

INT MANI PRES [kPa]

CONBUST CONDITION