2003 NISSAN TEANA check engine

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-37
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When there is an open circuit on MI circuit, the ECM can not warn the driver by lighting up MI when there is
trouble on engine control system.
Therefore, when Electrical controlled throttle and part of the ECM related diagnoses are continuously detected
as NG for 5-trips, ECM warns the driver that engine control system has trouble and MI circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit are detected and demands the
driver to repair the trouble.
MI Flashing without DTC
If the ECM is in Diagnostic Test Mode II, MI may flash when engine is running. In this case, check ECM diag-
nostic test mode. EC-37, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
How to switch the diagnostic test (function) modes, and details of the above functions are described later, EC-
37 .
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

Others
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.
Diagnostic Test
ModeKEY and ENG.
StatusFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MI bulb for damage (blown, open
circuit, etc.).
If the MI does not come on, check MI circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MI will light up to inform the driver that
a malfunction has been detected.
The following malfunctions will light up or blink the MI in
the 1st trip.

One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine running HEATED OXYGEN SENSOR 1
MONITORThis function allows the fuel mixture condition (lean or
rich), monitored by heated oxygen sensor 1, to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut

EC-38
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ON BOARD DIAGNOSTIC (OBD) SYSTEM


Always ECM returns to Diagnostic Test Mode I after 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.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MI starts
blinking.
4. Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).
How to Set Diagnostic Test Mode II (Heated Oxygen Sensor 1 Monitor)
1. Set the ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to EC-38, "How to Set Diagnostic
Test Mode II (Self-Diagnostic Results)" .
2. Start Engine.
ECM has entered to Diagnostic Test Mode II (Heated oxygen sensor 1 monitor).
How to Erase Diagnostic Test Mode II (Self-Diagnostic Results)
1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to EC-38, "How to Set Diagnostic Test
Mode II (Self-Diagnostic Results)" .
2. 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.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.
DIAGNOSTIC TEST MODE I — BULB CHECK
In this mode, the MI on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to DI-35,
"WARNING LAMPS" or see EC-344, "MI & DATA LINK CONNECTORS" .
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 MI as shown below.
The DTC and 1st trip DTC are displayed at the same time. If the MI 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 MI illumi-
nates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are dis-
PBIB0092E
MI Condition
ON When the malfunction is detected.
OFF No malfunction.

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-39
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played, 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-II. 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. The “zero” is indicated
by the number of ten flashes. 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 mal-
function. (See EC-10, "
INDEX FOR DTC" )
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 EC-
37, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .

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.
DIAGNOSTIC TEST MODE II — HEATED OXYGEN SENSOR 1 MONITOR
In this mode, the MI displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1.
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 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 MI
comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.
PBIA3905E
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system

EC-40
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BASIC SERVICE PROCEDURE

BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionBBS005BT
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no-
load.
6. Make sure that no DTC is displayed with CONSULT-II.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3
SEF983U
SEF976U
SEF977U

BASIC SERVICE PROCEDURE
EC-41
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3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-45, "
IDLE SPEED" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no-load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no-load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-45, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-47, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-47, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
SEF978U
700 ± 50 rpm (in P or N position)
SEF058Y
700 ± 50 rpm (in P or N position)

EC-42
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BASIC SERVICE PROCEDURE

6. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-47, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-45, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-45, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the Following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-176 .

Check crankshaft position sensor (POS) and circuit. Refer to EC-169 .
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of NATS system and registration of all NATS ignition key IDs. Refer to BL-139,
"NATS(Nissan Anti-Theft System)" .
>> GO TO 4. 700 ± 50 rpm (in P or N position)
700 ± 50 rpm (in P or N position)

BASIC SERVICE PROCEDURE
EC-43
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10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-45, "
IGNITION TIMING" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 11.
11 . PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-47, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-47, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-47, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Ye s > > G O T O 1 4 .
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4. 15 ± 5° BTDC (in P or N position)
PBIB2177E

EC-44
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BASIC SERVICE PROCEDURE

14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-45, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-45, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-45, "
IGNITION TIMING" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-53, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4. 700 ± 50 rpm (in P or N position)
700 ± 50 rpm (in P or N position)
15 ± 5° BTDC (in P or N position)
PBIB2177E